Americans of a certain age or of certain media consumption habits have a very particular cinematic association with the Senate filibuster.

There’s Jimmy Stewart, one of Hollywood’s first superstars, hoarsely exhorting his peers to reconsider a piece of legislation in “Mr. Smith Goes to Washington.” He has spoken for hours to broad indifference, growing weary but maintaining enough energy to hold a final vote on the bill at bay. He was doing it for the Boy Scouts, you see, and — with a wave of the movie magic wand — manages not only to carry the day but to get a corrupt senator to cop to his misdeeds from the Senate floor.

Like so many other Hollywood depictions of real life, this perhaps sets unrealistic expectations about what the filibuster is and what it is used for. In practical terms, filibusters these days are only rarely hours-long riffs driven by passion for a cause. They are much more frequently hand-wavey threats to offer such a speech, with the end game of forcing legislation to meet a supermajority standard before passage.

One of the regular points of discussion in Washington is whether such a tactic should be allowed. Parties in power are often eager to dump the tool to make it easier to pass legislation while those in the minority are usually eager to keep it. So it is now: Newly-minted Senate Minority Leader Mitch McConnell (R-Ky.) is holding up procedural process to get assurances that the Democratic majority won’t spike the filibuster.

So let us once again explain how we got to this point and what we can assume about what comes next.

How it emerged and evolved

The Constitution doesn’t say anything about a filibuster or about “cloture,” the legislative tool used to end the sort of speechifying that Stewart made famous. It was a tradition that the chamber would allow for unlimited debate — meaning that clever senators could delay votes indefinitely by appealing to that concept.

About 100 years ago, senators wised up. It established a rule not ending the practice entirely but, instead, establishing the cloture process for ending debate. At first, a two-thirds majority of those present and voting was needed to end debate. In 1975, that was reduced to three-fifths, which, with the current composition of the Senate, means that 60 votes are needed.

How it has been used

Let’s say you’re a senator who likes to stir things up and frustrate your colleagues. Say your name is Sen. T. Cruise, which is probably a reference to a famous actor and no one else.

Let’s say there’s a bill introduced that you and 40 other members of your caucus oppose. If the bill goes to a vote, you’ll likely lose, since up to 59 other senators might support the legislation. But you have an out: a filibuster! You could simply stand up and speak for hours and hours, delaying the vote and perhaps convincing those on the other side to share your position.

Or you could say, “I’m going to stand up and filibuster this thing unless you vote to stop it.” Skip all the talking and get right to the point, which is forcing the Senate to gin up 60, not 50, votes before a bill can pass. Much easier for everyone (except those who are die-hard about the idea that the majority should carry the day).

Over the past few years, there have been a lot of cloture votes in the Senate. According to GovTrack, there were 590 cloture votes from 1989 through 2009. Since then, there have been 930. Of those, 725 met the 60-vote threshold for cloture, and 141 of the votes got fewer than 50 votes in support of cloture. Another 654 votes, though, had the votes of at least 50 senators — but didn’t reach the 60 needed. So a majority supported ending cloture but the supermajority rule prevented that from happening.

The colored bars on that graph illustrate party control of the chamber, which represents the party that has either the majority or, as is currently the case, 50 votes plus the White House. (The vice president breaks any ties in the chamber.) We’ve also flagged the tenure of McConnell to highlight that his time as party leader has overlapped with an era in which cloture votes are the norm, not the exception.

From 1989 through 2006, about 7.8 percent of the roll-call votes cast in the Senate each year were for cloture. Since, a quarter of votes taken have been cloture votes on average. During the past six years, when McConnell led the majority, nearly a third of the votes cast were for cloture.

It’s gotten to the point that the filibuster is presented as a sort of intrinsic part of doing business in the Senate. In 2013 (back when cloture votes made up only 22 percent of roll-call votes), one senator even suggested that requiring 60 votes was simply how things should work.

“If this body votes to raise the debt ceiling,” the junior senator from Texas — one Ted Cruz (R) — said, “we should do so after a fair and open debate, where the issue is considered and where the threshold is the traditional 60-vote threshold and we can address what I think is imperative — that we fix the problem.”

If the 60-vote threshold is traditional, it’s a new tradition.

The efforts to scale it back

It’s also one that has already been rolled back.

In 2013, the Senate was controlled by Democrats, but only narrowly. Then-Senate Majority Leader Harry M. Reid (D-Nev.) had 55 votes in his caucus but was repeatedly unable to get presidential nominees confirmed because the Republican minority would force cloture votes. After months of threats and debate, Reid finally used what came to be called the “nuclear option”: The Democratic majority changed the rules to prevent presidential nominees besides Supreme Court justices from being filibustered. No filibuster, no cloture vote — and no 60-vote requirement.

Four years later, it was McConnell’s turn. Now Republicans were in the majority, but he only had 52 votes. Donald Trump had just been elected, and Democrats were eager to demonstrate their opposition to his nominees. That was particularly true of Trump’s nominee to fill a Supreme Court seat that McConnell had held open following the death of Antonin Scalia when Barack Obama was still president. So McConnell nuked the filibuster himself, removing the Supreme Court exception that Reid had included. Neil M. Gorsuch was narrowly confirmed.

The Democrats regained the majority on the strength of winning the White House in November and two runoff Senate races in Georgia earlier this month. With control of the House, many Democrats are eager to lower the bar for passing legislation in the Senate by eliminating the filibuster for any legislation, something Democratic leaders have been vague about endorsing.

The imbalance it allows

The Senate is already an institution that distributes power unevenly. States that make up only 16 percent of the country’s population cumulatively are represented by 50 senators, half of the total. Reduce the bar to 41 senators and you’re talking about just under 11 percent of the population. Meaning that senators representing a bit over one-10th of the country could block any legislation from passing.

In practice, it’s not quite that bad since the least populous states don’t share political alignment. But if we look at it in terms of presidential votes, states that made up only 13 percent of President Biden’s support in 2020 are represented by 50 senators. States that made up only 8.8 percent of the votes he earned control 41 senators.

The point, though, is that even achieving a majority in the Senate is already weighted to less-populous states, which often means more Republican ones. Raising the bar for passing legislation means weighting things even more favorably toward those states.

That initial imbalance was written into the Constitution, mind you. The filibuster was not — and is therefore endlessly under threat.

clarification

The description of the initial rules for invoking cloture was clarified.