Senate Minority Leader Mitch McConnell finally relinquished full control of the Senate to Democrats, agreeing this week to an organizing framework for the evenly split chamber. The breakthrough occurred when moderate Sens. Kyrsten Sinema (D-Ariz.) and Joe Manchin (D-W.Va.) publicly pledged not to eliminate the Senate's filibuster rule, which requires a supermajority of 60 votes to pass most pieces of legislation. McConnell, however, failed to get filibuster preservation in the organizing agreement, meaning that their more aggressive Democratic colleagues and the party's activist base will continue to lean on Manchin and Sinema to invoke the so-called "nuclear option," to kill the legislative filibuster.

The two moderate holdouts seem to sincerely believe requiring a supermajority to pass almost any law (outside of the arcane, once-a-year budget reconciliation process) helps foster bipartisanship. But they're wrong. Ending the filibuster is actually one of the last, best hopes of returning some minimal bipartisanship to Washington.

That probably sounds counterintuitive or even crazy. By requiring at least a bit of work across the aisle to pass almost any bill, doesn't the filibuster encourage moderation and compromise in what its defenders call "the world's greatest deliberative body"? No, it doesn't. What the filibuster actually fosters is acrimony and gridlock while empowering extremists who represent their Twitter feeds rather than their constituents.

For most of this century, the out-party's incentives have been quite clear. Making the president and his party look hapless and weak by holding up priority legislation in Congress has been a surefire route back into power. It's a strategy that demoralizes the other side's supporters by convincing them that even if they win power, nothing gets done. This cynical strategy worked for Democrats after George W. Bush was re-elected in 2004, and for Republicans under President Obama, and then again for Democrats under Donald Trump. In a closely divided country, even small shifts in turnout and support can lead to a power transfer, first in Congress and then at the presidential level.

If Democrats go nuclear, they won't just get to actually govern the country rather than trying to jam everything they want to do into a single reconciliation bill before kicking back and doing nothing until 2022, as some prominent liberals recommend. They will immediately change the strategic calculus in both parties, especially for moderates. And yes, those moderates still do exist.

One of the ways to conceptualize the ideological space in Congress is the Voteview project at the University of California-Los Angeles. Using roll-call data, researchers have produced an ideological score for every member of Congress going back to the 19th century.

According to this data, American politics hasn't been as polarized as it is today in more than a century. Yet three Democrats (Manchin, Sinema and the doomed Doug Jones of Alabama) were closer to the most liberal Republican Susan Collins (Maine) than to the average member of their own caucus. It's a similar story on the other side of the aisle, where Collins, Lisa Murkowski (Alaska) and Shelly Moore Capito (W. Va.) were all more similar to the most conservative Democrat, Joe Manchin, than they were to the average GOP senator.

That's not a lot of people, but these senators could, theoretically, be kingmakers in a narrowly split Senate. Yet on the important issues of the Trump era, like the nomination of Brett Kavanaugh to the Supreme Court and the GOP's 2017 tax cuts, almost all of them fell in line behind their party's position. Only Manchin among Democrats, for example, crossed over for Kavanaugh, when it was clear that Republicans had the votes anyway. On tax cuts, Democrats tried and failed to spike the legislation by picking off Republicans. Not only did Democrats not stop passage of the law, they received zero concessions for their trouble.

No one from this group of moderates played a meaningful role shaping policy. They were, instead, mostly spectators, because in the end party leaders wanted them on board, not negotiating with each other. Of course, the Tax Cuts and Jobs Act of 2017 was passed in the Senate with simple GOP majorities through the once-a-year reconciliation process, and the absence of the filibuster from the proceedings didn't lead to a flowering of inter-party cooperation. But reconciliation bills have become apocalyptic showdowns precisely because they are the only time majorities can act with fewer than 60 votes. If moderates and members of the minority party knew that these would be the dynamics of every single legislative negotiation over two years, their incentives would be quite different.

This all seems quite dumb when you step back and think about it. What if Senate majorities were simply allowed to pass legislation, which is the way it works in every other legislative body on the planet? While the U.S. two-party system is rare, supermajority requirements are not a feature of other presidential democracies, like Mexico, nor are they found in parliamentary systems like Canada or the United Kingdom.

What if no one in the minority party believed that they could use the filibuster rule to obstruct and humiliate their opponents and instead could only negotiate in good faith with their counterparts to craft legislation? The guess here is that it would open up some space for governing parties to produce bills that have some support from the opposition.

Under the filibuster rule, the minority leader's chief obligation is to keep the caucus voting together to obstruct the majority's agenda. Moderates, who might otherwise be inclined to band together with their counterparts across the aisle, instead see nothing but the possibility of getting back into power in the next election. It's a zero-sum game, so long as obstruction pays. And people like Collins and Murkowski will typically only defy leadership when their votes aren't needed — when the party leader has "released" them to take a vote that might play better in their home states.

The really critical way to think about filibuster reform is this: It takes control of the Senate agenda out of the hands of the minority leader. Remember, obstruction works not by producing resentment against single-party rule, but rather by creating the widespread perception that the president's party isn't getting anything done. If you vaporize the utility of obstruction by nuking the filibuster, you simultaneously free moderates from the grip of party leadership and empower them to work together as a small but crucial bipartisan bloc with effective veto power over legislation.

Democrats have the chance to change the national political environment for the better — not just to improve their own odds in the 2022 midterms and to make Joe Biden's re-election more likely by passing popular reforms, but to end the tyranny of the supermajority, empower both party's moderates to work together and to usher this era of ugly paralysis out the door. If they fail to do so, the Senate will continue masquerading as the site of compromise, when in reality it is where good ideas and bipartisan cooperation go to die.