Eliminating the Senate's filibuster has long been debated by senators and presidential candidates alike. The political tactic has made it nearly impossible for lawmakers to pass legislation and is what led the 116th Congress into becoming the least productive in history.
It is also what threatens everything that the Democrats have committed to do after the November elections. Now that the Democrats control the Senate, both sides of the aisle have, once again, become vocal in their support for or opposition to ending the filibuster.
The political procedure occurs when a senator speaks on the floor for a prolonged period, without breaks, as a way to delay voting on a proposed bill. To stop a filibuster and pass a bill, there needs to be a supermajority of 60 votes, which has become increasingly difficult to attain because of political divisions within the Senate.
The filibuster was born out of the absence of another Senate rule. At the advice of then-Vice President Aaron Burr, the Senate removed the "previous question" motion, which allowed the chamber to force a vote to move off a given topic, in 1806. Without it, a senator or impassioned minority could make a case for as long as they wanted.
In 1917, as a way to end filibusters, the Senate introduced cloture, which allowed two-thirds of senators to end the debate on "any pending measure." The threshold was lowered in 1975 when the number of votes needed to invoke cloture was reduced to three-fifths of the chamber, or 60 votes.
Cloture votes were not frequently used in its early days. For more than half a century, the Senate took, on average, one vote each year to break filibusters.
But over the past few years, cloture votes have become the norm. According to GovTrack, there have been 930 cloture votes in the past decade. On average, that comes to 93 votes a year. More notably, roughly seven in 10 of the cloture votes since 2010 had the votes of at least 50 senators but not the 60 required.

Eliminating the modern filibuster would mean discarding the supermajority in favor of a simple majority vote. The requirement for passing a bill in the Senate would then drop to 51 votes instead of the 60 currently needed.
The Democrats are now in a position to do this with their slight majority in the Senate. Using the "nuclear option," they could get rid of the 60-vote threshold to make it easier for President Joe Biden to push his legislation through. If the Democrats decide to keep the supermajority requirement, it's likely that some or many of the promises Biden made on the campaign trail will not get passed into law.
Even past Democratic supporters of the filibuster, including Senator Chris Coons and Biden himself, have said they would consider ending it, depending on how unwilling the Republicans are to compromise. But some Democrats, like Senators Joe Manchin and Kyrsten Sinema, present a new roadblock for their party.
On Monday, Senate Minority Leader Mitch McConnell backed off from his demand that Democrats guarantee they would keep the filibuster, after Manchin and Sinema said they remained opposed to eliminating it and would not vote to dismantle it.
Removing the filibuster would mean that if Senate control flips, the new GOP majority could use the 51-vote threshold to its advantage. Republican senators would then be in a strong position to push their legislative agenda.
Eliminating the filibuster would also hold lawmakers to greater account, because they could no longer advocate for policies they know will never get passed into law.
"Members of both parties prefer the problems of paralysis to those of governance," Vox journalist Ezra Klein argued. "They are more eager to block the other party from governing than they are committed to governing themselves. Or, to put it even more directly, given the choice between keeping the promises they made to the American people and sabotaging their opponents' ability to keep their promises, they choose the latter."
Without the filibuster, Senate Democrats could move to pass as many long-awaited bills—on voting rights, climate change, Medicare expansion and tax increases, among other matters—as possible. For now, the debate on the filibuster will continue, and the Senate will eventually face that critical moment when a specific bill gains the support of a majority but not a supermajority.