Britain’s political system is in crisis after Brexit. Shortly after voters decided that Britain should leave the European Union, David Cameron, the prime minister and Conservative Party leader, announced his resignation. This led to a short but vicious leadership contest, which left the ambiguous “Remain” supporter Theresa May as prime minister by default. The insecurity of May’s leadership is reflected in her decision to appoint Brexiteers Boris Johnson and Andrea Leadsom to important Cabinet positions, despite their obvious ambitions and even more obvious personality flaws.

Still, so far May is doing better than Jeremy Corbyn, the leader of the Labour Party and of Britain’s opposition. More than half of Labour’s shadow cabinet resigned or was sacked, and most Labour Members of Parliament (MPs) voted no confidence in Corbyn’s leadership, in a doomed effort to persuade Corbyn to quit. Corbyn refused to go, and in late September, he won the support of ordinary Labour members in a leadership election.

All this is likely to have a corrosive impact on British democracy over the next decade. The Labour Party is so weak that the Conservatives do not need to worry about Labour defeating them in the next election, or perhaps in the election after that. This means that UK political debate over the next decade will be an internal fight between more or less authoritarian versions of the right.

How did the UK end up in this bind? A few months ago, British politics appeared to be stable, if not particularly happy. The Conservative government had a narrower majority in Parliament than it wanted, but appeared likely to survive for a full term. Corbyn was detested by most of his senior colleagues. However, his leadership was probably secure until after the next election, which everyone expected to be a disaster for Labour, no matter who the leader was. Business leaders and pundits expected that the Brexit referendum would be won by the Remain side.

This stability masked deeper tensions. Like most sudden catastrophes, the Brexit crisis wasn’t nearly as sudden as it first appeared. Its main outlines reflected the claims of Peter Mair’s Ruling the Void, which was published posthumously back in 2013. Mair’s book identified the twin forces that are tearing at British politics today—the internal crisis of traditional political parties, and the external crisis of a cross-party establishment that has kept the issue of EU membership off the political agenda.

Peter Mair was an expert on European political parties. In the United States, political parties are relatively weak, and are seen as loose coalitions of politicians who often disagree with one another and vote against one another. In Europe, parties have more formal organization and play a key role in selecting leaders and prime ministers, disciplining parliamentary representatives, selecting candidates, and getting out the vote. But even as American parties have consolidated, becoming more organized than they used to be, European parties have been weakening for years.

In the opening words of his book, Mair wanted to know why “The age of party democracy has passed” in Europe. His answer was twofold. First, parties are coming under challenge from both below and above. Voters do not relate to them as they used to, and political leaders do not need them as much as they once did. Second, democracy itself is becoming weaker, as more and more of the actual business of government is farmed out to regulators, experts, independent bureaucrats, and, especially, the EU.

Mair argued that Western European political parties are only a faint remnant of what they used to be. Once, they were not so much party organizations as ways of life. If you were a supporter of the Dutch Christian Democrats, you very likely not only voted for them, but were a member of the party organization, read the party newspaper, went to party social clubs, married another party member, and together with your spouse brought up a new generation of little party loyalists. Parties appealed to class loyalties (workers had one party, bosses another) and ethnic and religious ties. (Some European countries had different parties for Catholics and Protestants.) Parties were electoral machines, but they also intermediated between ordinary citizens and the government. Leaders made the important final decisions, but were constrained by party structures, and had to listen to party supporters when they had something to say.

This has all changed. Class and ethnic and religious identities no longer provide secure foundations for European parties, which have more and more tried to become “catchalls,” appealing to wide and diffuse groups of voters. People are not attached to parties for life anymore, often waiting until just before Election Day to decide whom to vote for. Party membership figures across Western Europe have shrunk by more than half in a generation. In the UK, parties shrunk by two-thirds between 1980 and 2009, losing more than a million members, although Labour has recently reversed the trend.

Parties have changed at the top too. Party leaders don’t have the same incentive to listen to their base as they used to, because their base is now diffuse and ever-changing. This leads prominent politicians such as the former British Labour leaders and prime ministers Tony Blair and Gordon Brown to try to build their own brand by escaping or rejecting party politics. Blair famously claimed that he was never really a politician, while Brown told a party conference in 2000 that his job was to listen to the country, not the party. Party leaders tend instead to look to their peers, or business or interest groups (which provide them with money) more than to activists, supporters, or even sometimes elected representatives. Most importantly, senior party figures are increasingly embedded in the state, which provides them with government jobs when they win elections and financial support even when they lose. In most European countries, the state gives money to political parties that have passed a certain threshold of support, while some parties are able to apply for European Union funds too. For example, in Germany, parties that receive more than .5 percent support nationally are entitled to apply for funds. Parties that “respect European values” and have at least one member of the European Parliament are entitled to apply for EU funds too. Once, parties represented ordinary voters to the state. Now, parties represent the state to ordinary voters.

As European party leaders and elite party members became more embedded in the state, they began to cooperate tacitly with their rival parties to defend shared approaches to politics, forming a kind of cartel. Traditionally, parties have been composed of elites (leaders, members of parliament, or people holding other important elected or organizational positions) and ordinary party members (activists and others who pay a membership fee, participate in the party at the local level, and help out at election time). Now the elites tend more and more to view ordinary party members, who might jibe at accommodationism, as problems to be managed rather than resources to be deployed.

In Britain as in the United States, the advent of TV advertising and other technologies meant that elites relied less on ordinary party members to help get out the vote from the 1980s until very recently. Thus, they often try to reform party structures, sometimes in ways that appear superficially democratic (bringing in loosely committed supporters via postal ballots or mass meetings, for instance), but that are in part intended to drown out active party members.

As parties become more cartelized, they also become less ideologically distinct. Left and right parties come to cater to the same interests, sharing a rough consensus on how to manage things and building an establishment over time. Beneath their disagreements lie shared assumptions about politics—for example, that EU membership is valuable.

Mair, together with his colleague Peter Katz, argued that the cartelization of party politics has led to tacit collusion. This explains, in their view, why so many political decisions are being taken out of democratic politics in European countries, and given to delegated agencies, central banks, EU institutions, and the like—parties would prefer not to compete with each other on certain dimensions. In Mair’s description, the EU is a way for establishment parties to kick awkward political problems upstairs, and is specifically designed to make politics less democratically accountable. Mair exaggerated, although it is true that the EU’s democratic institutions are relatively unwieldy.

Thus, Mair claimed that mainstream political parties have fallen on hard times, because both ordinary citizens and political leaders are withdrawing from them. Ordinary people become ever less engaged with party organization, so that leaders in turn move away from their parties, leading ordinary people to yet again see less value in parties, in a self-reinforcing dynamic. As leaders become more embedded in the state, they tend ever more to shift uncomfortable issues such as immigration to the European Union or other nominally nonpolitical actors, such as central banks, independent regulators, commissions, and the like. Yet Mair stressed repeatedly that leaders are simply responding to the incentives that they face now that the traditional bases of party support—class and religious identity—have been eroded.

This cartelization gradually weakens mainstream parties. As Gary Younge has noted, the combined vote for Conservatives and Labour was 97 percent in 1951, but by 2015 it had slipped to 67 percent. It creates new opportunities for populist social movements on the left and right to challenge the mainstream, using the EU as a wedge issue. As Mair says:

hostility to European integration has become one of the best possible weapons in the political armoury of the anti-establishment forces. . . . the long march towards European integration has always been a project driven by Europe’s political and administrative elites . . . precisely because that consensus so self-evidently concerned an elite project, the European issue has become a hammer with which to beat the establishment.

Mair’s political ideals can be challenged. His purported golden age of party democracy was no idyll. Many groups—and indeed whole categories of human beings, such as women—got only token inclusion in decision-making. When party organizations were strong, they were not always democratic, or even representative, and were often captured by party hacks, self-servers, and monomaniacs.

Even so, Mair’s arguments provide apt tools to analyze the roots and consequences of the Brexit crisis. Brexit is a product of internal party politics: It happened because Conservative leaders wanted to head off a threat from within their own party, and to wrong-foot the UK Independence Party (UKIP). Yet its accidental consequence has been the devastation of the Conservatives’ main rivals in Labour.

Brexit’s roots lie in Euro-skepticism—political opposition to the encroachments of the European Union. Originally, Euro-skepticism was located in the left of the Labour Party, which saw the EU as a capitalist plot. But over time, certainly by the 1990s, most of Labour reconciled itself to Europe. Modern Euro-skepticism is primarily a movement of the right. The Conservative Party was nearly torn apart by fights about the European Union in the 1990s, leading then-Prime Minister John Major to complain about the Euro-skeptic “bastards” who were undermining him. The briefly lived Referendum Party, and the UKIP, which rose to prominence under the demagogic Nigel Farage, provided an independent right-wing (and sometimes extreme nationalist) voice for Euro-skeptics. Labour and the Conservative leadership both saw Euro-skepticism as a threat and tried to keep it contained, occasionally promising referendums to defuse tension around Europe, but repeatedly failing to deliver on their promises.

However, when the Conservative Party came back into power this decade in a coalition government with the Liberal Democrats, divisions between party leaders and rank-and-file backbench MPs flared up again. When a Tory backbencher proposed a motion in 2011 that the UK should have a referendum on EU membership, nearly half of the backbenchers voted in favor, even though party leadership had imposed a “three-line whip,” the most serious disciplinary measure available to it, to compel members to vote against it. Party leaders wanted to bury debate over Britain’s EU membership. Conservative backbenchers—sometimes egged on by local Conservative activists—wanted to exhume and reanimate the corpse.

Fears of a split in the Conservative Party and of a possible resurgence of the UKIP led Cameron to promise a referendum in a 2013 speech. Cameron hoped that he would have to go into coalition again with the pro-Europe Liberal Democrats, which would allow him to wriggle out of the promise, and he muttered that he preferred an alliance with the Lib Dems to Euro-skeptic backbenchers. Cameron furthermore expected that if it came to a vote, Britain would vote to stay in Europe. After all, everyone who mattered—business elites, experts, common-sense politicians—agreed that EU membership was a good thing.

Obviously, it didn’t work out that way. In the 2015 elections, the Lib Dems collapsed, and the Conservatives won a small majority. In his thus weakened position, Cameron had little choice but to go ahead with a referendum. However, he could not officially back the Remain side at first, since part of his strategy was to negotiate a better deal with the EU and only then sell it to voters. After he secured some modest concessions, he started to campaign in favor of Remain. But much of his party didn’t follow.

Labour faced a different problem. Most Labour MPs were pro-Europe, as were most members of Labour’s leadership. However, Corbyn was a stalwart of Labour’s left and was one of the very few Labour MPs to vote in favor of a referendum on EU membership in 2011. Unsurprisingly, his campaign for the Remain side was half-hearted. These difficulties meant that most of the actual campaign planning for the Remain side was organized by the outside group Better In, which drew support from senior strategists and politicians from all three major parties. These people had different political affiliations but a common world view—as one of them described it, “We were the pluralist, liberal, centrist force in British politics.”

The problem was that they did not realize how vulnerable the tacit cartel of pluralist liberal centrism was to populism. The British political scientist Chris Gifford built on Mair’s arguments in 2014 to explain how Euro-skepticism and populism had become fused together in British political discourse. Both left-wing and right-wing Euro-skepticism claimed to act in the name of “the people,” who had been betrayed by elites into subordinating Britain to Europe. Popular myths—some of them actually started by Boris Johnson when he was the EU correspondent for The Daily Telegraph—portrayed a Brussels bureaucracy intent on undermining the most treasured aspects of British life. These were myths, but they reflected the truth that key decisions affecting sensitive topics such as immigration were increasingly made outside Britain, with the full cooperation of British leaders and high officials. It was easy for campaigners and tabloid journalists to weave together rhetorical claims about immigration, Brussels bureaucracy, and out-of-touch politicians into a populist case for leaving the European Union. In Rafael Behr’s description, pro-EU membership campaigners were “the informal party of defensive liberalism—the unpopulists,” and to their horror and amazement found themselves losing the Brexit vote, by a 52-48 margin.

If the referendum was a Conservative mistake, it was Labour’s disaster. How did Labour get into this mess? The Brexit referendum sparked the crisis, but the true causes lie in Labour’s earlier responses to the problems Mair identifies.

The UK Conservative party has typically looked to attract passive supporters and now has an elderly membership: Most are 60 or older. In contrast, the Labour Party is a mass organization, which has always relied on a broad membership of active supporters. This has been a blessing and a curse for its leaders. The organization has provided Labour with troops on the ground, but it has also made it harder for leaders to change the party’s direction. Reforming the Labour Party has not just involved changes in policy but in organization.

Over the last 30 years, Labour’s leaders have tried to reform their party organization so as to minimize the influence of activists and unions. They partly succeeded, but only at the cost of creating a self-perpetuating leadership class within the party, which looked to Whitehall (where the UK government resides) rather than to constituency organizing.

When the party was comprehensively thrashed in successive elections during the Margaret Thatcher era, Labour leader Neil Kinnock and his successor John Smith believed that party activists were to blame. They tried to reform the party to sideline activists and expand the influence of members who didn’t often turn up at meetings, thinking that the latter were likely to be more moderate and sensible. In 1993, the selection of candidates was opened up to all party members—not just appointed delegates.

When Tony Blair became leader, he too wanted to bring Labour closer to the center of British politics, both out of personal conviction and to make the party more electable. To do this, he needed to circumvent left-leaning party activists and unions, which were able to influence both the choice of candidates for Parliament and the selection of the party leader. Blair first got rid of the famous clause in the party’s constitution advocating common ownership of the means of production by putting it out to a ballot of all members in 1994, undercutting opposition from some MPs and from left-leaning trade unions. In 1996, Blair undertook another ballot on the Labour manifesto, which again was not intended to give ordinary members a role in setting policy so much as to show that the rank and file supported his reformist politics.

These changes helped Blair and his immediate successor, Gordon Brown, move Labour to the center and got it elected to government three times. However, they led to continuing internal fights over who should control the organization. Unions continued to have influence because they provided the money—Labour’s efforts to raise funds from other sources such as business were only sporadically successful. However, Blair, Brown, and those around them were also able to exert influence from the top. The result was that the paths to influence and opportunity within the party led either through unions or government connections. Union political employees, think-tankers, “SPADs” (special temporary advisors to government ministers), and parliamentary researchers made up a new and self-perpetuating leadership class, which was increasingly disconnected from the ordinary party organization. Membership of the Labour Party didn’t mean much anymore, and membership numbers collapsed. By 2011, Labour’s membership was 40 percent of what it had been in 1997, when the party came to power.

This approach—of treating ordinary members as a ventriloquist’s dummy—changed when Ed Miliband became leader. Miliband wanted to give party members a genuine sense of involvement and decision-making power. He opened up party membership—not in order to dilute the influence of activists, but because he hoped it would build on the energy of the community and get ordinary supporters directly involved in politics. Miliband also gave members a more direct role in electing the party leader, thus opening the door for Corbyn’s election.

As Miliband described the problem:

[L]et’s be honest, the leadership believed its role was to protect the public from the party. It never really believed the party could provide the connection to the British people. And we didn’t build a genuine movement. By the end, it was our party members that were trying to tell the leadership what people wanted it to hear . . . But the leadership did not listen enough. So we went from six people making decisions in a smoke-filled committee room in the 1980s to six people making the decisions from a sofa in Whitehall. Old Labour forgot about the public. New Labour forgot about the party. And, by the time we left office, we had lost touch with both.

As Tim Bale documents in his book Five Year Mission, Miliband believed that Labour could build up its grassroots again by looking to community-based organizations like Movement for Change, a community activism group associated with Labour, which described itself in vague yet messianic terms as “an experiment in democracy and the exercise of civic power.” He started internal consultations over how best to rebuild the connection between Labour and the public.

After a controversy about union shenanigans, he was able to persuade the party to adopt sweeping new reforms. Previously, party leaders had been elected under a system where one-third of the votes were cast by MPs, one-third by unions, and one-third by ordinary Labour Party members. Now, the MPs would select candidates for the leadership; any candidate would have to win support from at least 15 percent of MPs, unless he or she was the incumbent leader and wanted to run again. The candidates selected by MPs would be put up for an election in which any party members could vote, including “registered supporters”—a new kind of limited member who could sign up for only £3 (just under $4). Unions would no longer have a block vote—but individual union members could join the party and vote that way.

Miliband anticipated that this would attract people to become party members. His hopes were justified—but only after his own defeat. After the 2015 election, membership nearly doubled in a year, jumping from 201,000 members to 388,000. Some of the new members belonged to unions—including left-wing unions that were not affiliated with the party—that mobilized them to join. Others joined for individual reasons. Research by Tim Bale, Monica Poletti, and Paul Webb shows that these new members tend to be well-educated and heavily left-wing. They wanted to join the Labour Party to remake it into an unapologetically left-leaning party. However, the research suggests that they aren’t prepared to put in the hard grind. While most of them have posted about Labour on social media or signed a petition, more than half have never attended a constituency meeting, and only a small minority have gone door to door or delivered leaflets. They are at best a shaky foundation for remaking the Labour Party.

But these new members are the reason why Jeremy Corbyn became Labour’s leader. Corbyn was a reluctant nominee. He did not run because he thought he could win, but because someone had to represent the left in the leadership contest, and no one else wanted to do it. He only just got the necessary 15 percent support among MPs to make it onto the ballot paper, and that because a few MPs felt sorry for him. However, it soon became clear that he was anything but a token candidate—polls showed that he was leading and constituency organizations started to endorse him. Despite a concerted push from previous party leaders Blair and Brown, and from MPs aghast at the prospect of having him as leader, Corbyn romped to victory with nearly 60 percent of the votes.

After this victory, Corbyn reached an armed detente with senior Labour MPs, under which each was prepared to tolerate the other until circumstances provided one side or the other with a decisive advantage. However, this detente broke down after the Brexit vote. Labour MPs saw the debacle as an opportunity to force Corbyn to step down, fearing that he would lead the party to electoral catastrophe if he won. However, despite the resignation of most of the shadow cabinet, Corbyn refused to go, forcing the September leadership contest. He won it with an even higher percentage, by a couple points, than his initial victory, despite efforts by Labour’s National Executive Committee to disqualify new Labour members who were likely to support Corbyn.

The modern Labour Party is caught in an especially unpleasant version of Mair’s dilemma. Labour’s leaders tried over decades to improve the party’s electoral prospects in a country where its traditional class base was disappearing. They sought very deliberately and with some success to weaken its party organization in order to achieve this aim. However, their success created a new governing class within Labour, one largely disconnected from the party grassroots that it is supposed to represent.

Ed Miliband recognized this problem as party leader and tried to rebuild the party’s connection to its grassroots. Instead of opening up membership to dilute the influence of activists, he tried to get members involved, by simultaneously loosening the requirements for party membership and giving members a much bigger role in choosing leaders. However, as Mair might have predicted, there weren’t any traditional grassroots out there to cultivate. Instead, Labour has attracted a flotsam of temporary activists who do not seem willing to engage in the slow boring of hard boards that would actually be required to remake the party. Mair argued that the leadership and the base were becoming disengaged from each other, so that traditional parties were withering away. Labour has actually taken this one stage further, creating a party in which the leadership and membership are at daggers drawn, each able to stymie the other, but neither able to prevail or willing to surrender.

After Brexit, the British political system is starting to come to terms with the problems that Mair identified. The Conservative Party, having toyed with populist opposition to European Union membership for decades, now has to negotiate the terms of Britain’s exit. Theresa May appears to have decided to harness the forces of populism rather than oppose them, proposing a “fairer” Britain, in which inequality will be lower, the government will play a much more active role . . . and businesses with foreign employees will be obliged to report on them. She intends to steal Labour’s working class support, leaving it with only a small coterie of liberal do-gooders. Like Miliband, May wants to rebuild the connection between her party and a broader public. She may do better than Miliband did: Strong state populism might offer a more enduring and attractive political identity than diffuse communitarianism.

May—and any putative Conservative successor—will likely have time to experiment with her message. If the Conservative Party is trying to wriggle off one tine of Mair’s argument, then Labour has been impaled by the other. Now that Corbyn has won the leadership election, he is proposing to increase the role of party members in making policy and in selecting members of the National Executive Committee. His supporters are looking forward to working in local branches to “deselect” MPs who voted against him—Corbyn has offered ambiguous assurances that the “vast majority” of MPs have nothing to fear, but that the politics of how local parties select MPs is “complex.” Over the next couple of years, the Labour Party is more likely to be consumed with its own internecine warfare and disarray than the difficult task of figuring out how to win elections again. Institutional reforms such as the membership selection of MPs that were intended by centrist reformers like Kinnock and Smith to weaken the grip of activists are now empowering them.

However, even if Corbyn’s enemies were to win an improbable victory, they are unlikely to be able to do any better, welded as they are to a hostile membership and the discredited policies of the Blair era. British voters may dislike and distrust Corbyn, but they detest Tony Blair—a recent poll suggests that Labour support would fall to just 15 percent if Blair returned as leader. Labour’s problem is not that the wrong people are in charge. It is that the problem of increased distance between ordinary members and party leaders is being reinforced, rather than remedied, by the institutional reforms that were meant to break the vicious circle.

If Conservatives inadvertently set the trap that Labour has stumbled into, the Labour Party’s difficulties are causing problems in turn for Conservatives. One key reason why May is adopting a hard populist line is that she fears if she does not, her Euro-skeptic rivals would challenge her leadership and win. After all, they have no reason to fear losing their seats. When there is no effective opposition party, nor the prospect of one in the foreseeable future, there is no external enemy that might unite the party in power and prevent it from gnawing on its own entrails. Yet as the Conservative Party moves ever further to attract Labour supporters, the Labour Party is likely to become increasingly disconnected from what bases of support remain to it.

Together, these factors mean that there is little prospect of Britain facing up to the real challenges of Brexit. May’s populism effectively commits the UK to a “hard Brexit,” in which it will close its borders to EU workers, while the EU will close its borders to UK services and London’s financial industry. The Labour Party, which is embroiled in a continuing civil war, is unable to offer any clear vision at all.

Even so, the question of the UK rejoining is likely to come up again, as the costs of continued exclusion become clearer. Britain’s strategic situation in the world economy has not changed—it is far more dependent on Europe than it would like to admit. More than 4 million UK citizens signed a petition to run the referendum again—those who voted for Brexit tended to be old, while those who voted in favor of remaining in the EU tended to be young.

This might create political opportunities for an opposition party that wanted to oppose May’s vision of Britain by advocating a more populist vision of the EU—one in which people had free movement, but technocracy was curtailed and ordinary people had a better chance to shape policy. Such a vision might help mobilize the very large numbers of British people who wanted to remain within the EU around an active and positive agenda. It might also answer Mair’s dilemma—by proposing reforms that would once again build bridges of mutual accountability between citizens and their elected representatives. Finally, it might create alliances with other nascent reformers that are starting to think through the problems of Europe. Perhaps a reformed Labour Party could build on such a vision or something like it, but there is precious little evidence of it right now. Even if it did, there is no guarantee that this vision would lead to election victory.