The Democratic Party has changed less in recent years than many Americans, both left and right, imagine. Indeed, it has changed less in the last century than many contemporaries believe. During the two-term presidency of Woodrow Wilson (1913 to 1921), Democrats were responsible for helping to enact a graduated income tax, bolster federal regulation of the economy, and commit the United States to playing an unprecedentedly large role in international affairs. The Party continued to fight for these principles throughout the presidency of Franklin D. Roosevelt, who rolled out the New Deal and led the United States into the position of global hegemony it has enjoyed, for better or worse, ever since. However, despite the striking persistence of those commitments, the mere mention of Wilson suggests the most consequential change in the Democratic Party, a change that has transformed American politics over this past century: the Party’s gradual rejection of white male supremacy and its commitment to equal rights for women, African Americans, ethnic minorities, and, more recently, the LGBT community. That reorientation, while strengthening the party’s appeal to many voters, has cost it others; the resulting realignment created our current condition of inequality and increasing political and ideological polarization.

The Democratic Party remains an unstable coalition, as all major parties in U.S. history have been. Ever since Republican strategists exploited Lyndon Johnson’s grudging embrace of the civil rights movement to capture the South, Democrats have attracted shifting sets of voters, while continuing to pledge themselves to a strikingly consistent set of objectives. Overall, they have aimed to secure wider economic and social opportunity for all Americans, including women, and racial and ethnic minorities, by raising the minimum wage, supporting unionization, and instituting a more progressive tax system to reestablish the obligations of the wealthy. They have called for more robust government regulation of the economy, in the interest of workers and consumers rather than industrialists and financiers, and investments in public goods such as infrastructure, education, and the environment. And for most of the years following LBJ’s presidency, they have been more wary about flexing American military power overseas than Republicans have.

A quick glance at Democratic Party platforms in the past half century highlights the persistence of these concerns, while it also makes clear that the supporters of Bernie Sanders had a point when they demanded that the party emphasize its longstanding commitment to egalitarian principles. In 1972, for example, the party platform called for “economic justice” to address the ownership of 90 percent of “productive national wealth” by 5 percent of the population. It pledged to provide “a guaranteed job for all” who sought to work, fix the “regressive” tax system, raise and expand the coverage of the minimum wage, establish a system of universal health insurance, and withdraw immediately from Vietnam. Twelve years later, in 1984, the Democratic platform was still echoing many of the same ideas. It promised, among other things, to reform a tax code that was shifting the burden from the rich to the poor and middle class, exposed the fallacies of “trickle-down economics,” and urged arms control rather than saber rattling.

However, there have been exceptions to the continuity of the Democratic Party’s commitment to these ideas, most notably in 1992 and 1996. In those years, the party repudiated its social democratic heritage and committed itself to a “third way,” a more moderate approach said to reflect Democrats’ latent disagreements over issues ranging from abortion and capital punishment to crime and gun control. The platform still called for tax reform and investments in education, infrastructure, and the environment, but it asserted that the time had come to stop trusting the federal government to solve every problem. Of course, as readers of Democracy know, in 1972 George McGovern carried only the Commonwealth of Massachusetts, while in 1984 Walter Mondale carried only Minnesota (although both carried Washington D.C.). Bill Clinton, on the other hand, rode his strategy of triangulation straight to the White House.

Because the Democratic Party remains a coalition of very diverse groups of people, its platform, despite its persistent emphasis on the problem of economic inequality, has most often embodied strategic compromises and calculations. The idea that it must always stringently adhere to a particular set of fixed principles and policies shows a misunderstanding of how and why U.S. parties have flourished—and how democracy must work. Spirited debates over ideals, as well as strategy, are the lifeblood of party politics; it’s how parties evolve. In a two-party system, though, erecting a big tent has been the price of victory. And, for Democrats in 2016, that tent must encompass increasingly fractious groups, including, among many others, blue- and white-collar workers pessimistic about their prospects; African Americans and recent, often Hispanic, immigrants resentful of secular professionals who claim to embrace diversity while mocking conservative Christians; public employees convinced that they, and not Silicon Valley entrepreneurs or Hollywood moguls, are the party’s conscience; millennial hipsters impatient with older Americans who resist the future; and diverse groups of impassioned environmentalists, who worry less about unemployed coal miners than about rising sea levels. Perfectly reconciling the concerns of such diverse voters in a single set of proposals is simply impossible. Only during the administrations of FDR and LBJ did Democrats enjoy Congressional majorities strong enough to enact the ambitious legislation proposed by the White House, and, even then, their opponents—including southern Democrats who remained powerful party leaders—managed to alter the party’s plans to suit their prejudices.

Notably, the Democrats’ embrace of increasingly large numbers of racial and ethnic minorities has been mirrored by opposite changes in the Republican Party, which has resulted in the emergence of parties more ideologically consistent than they were for much of U.S. history. The early twentieth-century Republican Party included champions of progressive social and economic reform as well as captains of industry and finance. But ever since the mid-1960s, the Republican Party has been, in the words of historians Bruce Schulman and Julian Zelizer, “rightward bound,” both on cultural issues and on economic ones. While Republicans, as E. J. Dionne shows in his recent book Why the Right Went Wrong, were busy enforcing ideological purity, Democrats have been struggling to reconfigure the New Deal coalition in the space between McGovern, Mondale, Sanders, and Warren, on the one hand, and Jimmy Carter and Bill Clinton on the other. Even moderates, such as Carter and Clinton, however, found themselves able to enact legislation only during the first two years of their presidencies, when they enjoyed wafer-thin Congressional majorities, and then only when their initiatives—such as deregulating the finance and housing sectors; embracing the mantra of “law and order”; and ending “welfare as we know it”—resonated with conservatives. The Republicans’ increasingly shrill denials of the legitimacy of government spending and social programs, their rejection of all economic regulations as job-killers, and their reliance on military power as the solution to every international problem constitute striking departures from their earlier traditions.

The transformation of both parties cannot be disentangled from the emergence of new forms of media that have intensified citizens’ partisanship and tribalism. Americans increasingly inhabit echo chambers, not only in terms of what we read and watch, but also where we live and those with whom we interact. That insularity, as many scholars have shown, reinforces the increasingly rigid positions taken on both ends of the political spectrum, a dynamic that makes people ever angrier and renders democratic deliberation and reasonable compromises less and less likely. The hollowing out of the political center, exacerbated by the 2010 reapportionment that has rendered so many Congressional races uncompetitive, has meant that Democratic as well as Republican candidates worry more about satisfying activists in their own parties than about forging bipartisan compromises.

Nothing shows the depth of the problem more vividly than the fate of President Barack Obama. Able to overcome centuries of racial prejudice only because of a severe economic collapse, he arrived at the White House determined to bring Americans together. Although he had succeeded as a conciliator in the contentious worlds of community organizing, law, and state and national legislatures, as President, even the most moderate of his proposals, from the stimulus package and the rescue of banks and auto companies to a health-care program designed by a Republican think tank and enacted by a Republican governor in Massachusetts, were greeted by outrage and denounced as socialist by the right and as surrenders by the left. Since the Democrats lost their narrow majority in Congress two years into his presidency, all of his initiatives have been blocked and he has accomplished very little. Yet conservatives still denounce him as a dictator and radicals dismiss him as spineless and ineffectual.

So we find ourselves, on the eve of the election of 2016, with a fractured polity and two flawed nominees whose favorability ratings have sunk lower than those of any candidates since the dawn of polling. Hillary Clinton has been the target of Republicans’ ire ever since she arrived on the national scene as the face of her husband’s health-care initiative. Like President Obama, she embodies everything conservatives hate. She is a well-educated policy wonk who has spent her adult life working to use the power of government to improve the condition of women, children, and poor people. Hate-filled diatribes spewing from her opponents guarantee that, even if she is elected, her foes will judge her corrupt, illegitimate, and contemptible—as they did her predecessor. Republicans in Congress would be unlikely to cooperate with the first female President after she has been subjected to decades of abuse. Hillary Clinton has succeeded in winning the nomination of her party with a shrewd sense of how to construct an electoral majority around the sturdy communitarian anthem “better together.” Yet it is hard to see how she, or anyone else, will be able to bring together a nation that has seldom been as polarized—on cultural as well as economic issues—as we are today. Democracy requires an ethic of reciprocity, a willingness to allow your worst enemies to govern if they win an election. That precondition of self-government is now at risk.