A frequent sight on C-SPAN’s feed from the Senate floor over the last few years has been a senator passionately pleading for the institution to consider some new idea or piece of legislation, while acknowledging that such entreaties would leave the diffident Majority Leader, Mitch McConnell, unmoved. From Mark Warner to Josh Hawley, senators from both parties, all ideological factions, and all levels of seniority have run up against the same impassive resistance.

Watching these sad spectacles from the perspective of a former Senate staffer, albeit from the 1990s, I wanted to shout at the TV: “Here’s how you get the Senate to consider your idea: You stand up, ask for recognition and say, ‘I’ve sent an amendment to the desk and ask for its immediate consideration.’” After that, the Senate might take up the amendment, debate and vote on it, or the senator proposing it might agree to withdraw it in exchange for, say, a promise by a committee chair to hold hearings on a freestanding bill. The privilege of being a U.S. senator means that you don’t have to ask permission to offer an amendment.

But that experience is as outdated as “I’m just a bill…” McConnell, expanding on a precedent set by his immediate Democratic predecessor, Harry Reid of Nevada, routinely employs a once-arcane tactic known as “filling the amendment tree” to ensure that there’s no opening for new initiatives. With all available slots for amendments occupied by placeholders that change only a word or two, the majority leader can exercise absolute control of the agenda, leaving individual senators irrelevant pawns, politely asking for a chance to participate.

In his book Kill Switch, Adam Jentleson, a top aide to Reid until the latter’s retirement in 2017, captures the evolution of these and other changes in rules and culture that have transformed the Senate from an occasionally open and productive legislative body into a rigid and insular one in which little matters other than the partisan body count, which is in itself profoundly unrepresentative of the preferences of voters as a whole.

Because the book arrives at a moment when the legislative filibuster is the hinge on which voting rights and most of President Biden’s agenda after the American Rescue Plan (passed through a tortured budget procedure that requires only 50 votes) depends, Kill Switch has been read mostly as an extended case for filibuster reform. Its author spent the first months of 2021 making the rounds of MSNBC panels to make that case to the already-convinced. In tracing the filibuster back to its roots in the pro-slavery pretextual political theory of John C. Calhoun and its deployment to delay civil rights legislation for many decades, while at the same time showing that the filibuster-as-supermajority is not rooted in the structure or any original conception of the Senate and has been changed often, Jentleson makes an entirely persuasive, historically sound, well-researched case.

But in the scaffolding around this timely policy argument there’s a much more complex story about the Senate as an institution and its role in American democracy. The filibuster is part of that story, but far from the whole of it. Jentleson’s chapter about Reid, a fascinating politician, soft-spoken and strategically brilliant, adds a compelling personal narrative and shows the Senate through the complex choices of a leader who wanted to respect the institution’s traditions and his colleagues, but who was also determined to get past McConnell’s endless obstruction of President Obama’s policies and nominees. A particularly useful section rediscovers the role of Jesse Helms, the hate-filled North Carolina Senator who often paralyzed the Senate, not so much with filibusters, but with endless homophobic and racist amendments and procedural moves. Helms was erased from the conservative pantheon as an embarrassment the moment he retired in 2003, but his obstructive and disruptive tactics, including building one of the first freestanding ideological fundraising operations, the Congressional Club, remain central to the operations of what Jentleson calls the “super-minority” that still dominates legislative politics.

Jentleson’s clever title refers to the idea that the Senate, in its combination of  disproportionate representation and the filibuster, “has become a kill switch that cuts off broad-based solutions and shuts down our democratic process.” But there’s another way to read the phrase, in which it’s the Senate itself that has been abruptly shut down. An institution that at times has had the potential to identify “broad-based solutions” and find occasional consensus has been stripped of that capacity, by McConnell for sure, but also by Reid, in response to McConnell’s obstruction while in the minority.

McConnell on March 16 defended the filibuster in familiar terms: Without it, “the Senate would cease to be distinct from the House in any respect.” The suggestion that the Senate could become like the House of Representatives triggers an age-old contempt, fully reciprocated, by the members of the “upper body” toward their plebeian counterparts. (Of a forgettable and forgotten two-term senator of the 1990s, an older staffer once whispered to me, “That guy’s one of our House members.”) By “like the House,” they mean tightly controlled by the majority, with limited opportunities for not just the minority, but individual members and coalitions in either party, to influence legislation or put their own ideas on the agenda. A House member follows the rule “go along to get along,” attributed to the mid-twentieth century speaker Sam Rayburn, until possibly becoming a committee chair at an advanced age.

The Senate, by contrast, believes itself to be the home of individualistic policy entrepreneurs, with the privilege of worrying about reelection infrequently, who can form fluid cross-party coalitions, develop deep issue expertise, and put their causes on the national agenda. It’s a heroic story told in many older books about the Senate, such as Eric Redman’s The Dance of Legislation(1973), The Senate Nobody Knows by Bernard Asbell (1978), or even a more recent book, Lion of the Senate, about the last years of Ted Kennedy’s Senate career when he held little formal power but was able to form coalitions to achieve incremental progress.

The absurdity in McConnell’s argument is that the Senate some time ago, on his watch, became all but indistinguishable from the House. The futility of long-serving mainstream senators as they beg for the chance to propose just about anything makes their preening self-importance almost laughable. Further, as James Wallner, a former Republican staffer now at the R Street Institute, points out often, the closing of the Senate depends on the tacit cooperation of almost all the senators of the leader’s party. A few members of McConnell’s caucus could at any time have resisted his tactics and reopened the door through which they could bring their pet ideas, such as Hawley’s proposed changes to the laws affecting Big Tech and social media companies, to the agenda. They chose not to. Just as they chose never to cross the line that might provoke a mean tweet from Donald Trump.

And with rare exceptions, such as Mitt Romney’s proposal for an expansive benefit for families with children, the 50 current Republican senators don’t seem to have much to put on the agenda anyway. Content to hold out until the next opening for tax cuts, while “owning the libs” and ranting about “cancel culture” and Dr. Seuss, they’ve largely abdicated any constructive role in governance, content to follow McConnell’s cold tactical guidance, or maneuver to claim Trump’s constituency for their own presidential ambitions. Political scientist Sean Theriault usefully tagged a subset of them in a 2013 book the Gingrich Senators,  shaped by the unending and vacuous partisan warfare of the 1990s House. “One of our House members” is no longer much of a distinction.

The same year Theriault’s book came out, Norman Ornstein, the political scientist who has done the most to call out the extremism of the current Republican Party, argued that then-recently elected senators including Elizabeth Warren and Tammy Baldwin, along with those who arrived in 2006 and 2008, could constitute a “third golden era of Democratic senators.” The previous two golden eras involved legendary senators who served in the 1960s, such as Edmund Muskie and Warren Magnuson, and those who arrived in the post-Watergate class of 1974—many of them the heroes of those earlier Senate books. (Interestingly, President Biden served alongside many senators of the first era and all those of the second.)

Ornstein is right, and Democratic senators elected in the last 15 years, from Hawaii to New England to the two elected from Georgia just this year, have all shown capacity for greatness. And the Democratic caucus is also more representative than those “golden era” Senates, which were all white as recently as 2004 and all male as late as the mid-1970s. But in the current institution, much of that talent is wasted. Compared to those older Senate books, Jentleson’s feels like the last volume in a long saga of a once-noble family, in which the heirs idle away their days in a vast mansion full of portraits of their predecessors.

A Senate without the filibuster in its current form as a de facto supermajority requirement will be far less of an obstacle to democratic governance than it has been in the recent past. It will not be a majoritarian institution, as long as a state with 40 million people has the same representation as one with 600,000, but at least it would not so fully empower a super-minority.

But shouldn’t we expect more from the Senate than merely that it not be an obstacle? It’s the rare legislative body anywhere in the democratic world that, in theory, gives individual members so much freedom of movement. Reopening its potential would involve far more than just ending the filibuster. It would have to include changing practice to allow real amendments, open committee markups, and full debate—reforms Jentleson alludes to in a brief conclusion. On its own, filibuster reform might actually narrow the opportunities for amendment and debate, without other reforms to the rules of debate post-cloture, that is, after a filibuster has been ended, whether by 60 votes or 50.

But it also requires some of the cross-party and cross-ideological fluidity that characterized more productive eras, and that in turn may not be possible without more dramatic reforms that would allow multiple parties to thrive, as Lee Drutman has proposed in his book, Breaking the Two-Party Doom Loop. And it’s certainly impossible if 50 percent of the institution is resolutely uninterested in participating in constructive debate and governance on most issues.

If those things don’t change, then filibuster or no, the U.S. Senate just might not be an institution worth keeping, despite its brief episodes of glory in the past.