Are Filibusters Effective? Blocking, Compromise, and Endurance

Are filibusters effective? At their core purpose — stopping legislation a Senate minority opposes — yes, decisively. At the secondary purpose defenders claim for them, forcing bipartisan compromise, sometimes. And at governing a modern Senate, the record is worse: the 60-vote threshold now blocks bills that never even reach the floor, and much of what used to be ordinary lawmaking has been rerouted around it. Whether that adds up to a working institution depends on what you think the Senate should be doing.

What “Effective” Means Here

A filibuster works by exploiting the Senate’s tradition of unlimited debate. Ending debate requires cloture, and since 1975 cloture has required 60 votes out of 100.¹ Once cloture is invoked, the final vote itself takes only a simple majority.² The practical consequence: a bill with 55 supporters can be stopped by 41 opponents who refuse to allow the vote.

Two 1970s reforms made filibustering nearly costless. The two-track system, introduced by Senator Mike Mansfield in 1972, let the Senate set aside a filibustered bill and move on to other business. The 1975 threshold change dropped cloture from two-thirds to 60 votes. After those changes, a group of 41 senators no longer needed to hold the floor and speak. They could simply announce they would block cloture, and the majority leader, knowing he lacked the votes, would pull the bill. Scholars Catherine Fisk and Erwin Chemerinsky described the result as a system where “a Senator could filibuster without uttering a word on the Senate floor.”³

The volume shifted accordingly. From 1917 through 1970, fewer than 60 cloture motions were filed in total. By the 2000s, the Senate averaged 53 per year. The 117th Congress (2021–2022) alone saw 336 cloture motions filed.⁴ What was once an act of physical endurance became a routine procedural filing.

How Effective at Blocking Bills

By this measure, extremely. Political scientists Sarah Binder and Steven Smith, analyzing 1917 through 1994, identified dozens of measures that were derailed by filibusters despite majority support in both chambers and likely presidential approval.⁵ An analysis by the Center for American Progress found that before 1880 “almost every filibustered measure was eventually passed,” because the tactic mostly delayed legislation. In the modern era it routinely kills bills outright, producing what the analysis calls “automatic failure for bills not reaching the 60 mark.”⁶

The clearest examples are recent and specific. During the Obama administration, the House passed the American Clean Energy and Security Act, but the Senate never brought it to a vote because supporters conceded they could not reach 60. A public option was cut from the Affordable Care Act after Senator Joseph Lieberman announced he would oppose cloture. After the Sandy Hook shooting, a bipartisan background-checks bill got 54 votes and failed. The DREAM Act was filibustered in 2007 and twice in 2010.⁶

The blocking effect that never shows up in cloture counts is anticipatory. One study found that “the inaction that results from anticipated filibusters is almost certainly more consequential than the inaction that results from actual filibusters.”⁶ Bills get shrunk, dropped, or never drafted because the drafters already know the 60th vote is not there.

The longest continuous record of successful blocking is civil rights. Anti-lynching bills were filibustered in 1922, 1935, and 1938. Anti-poll-tax bills were stopped in 1942, 1944, and 1946.⁷ One analysis found that from 1877 to 1964, the only category of bills successfully killed by filibusters were civil rights measures.⁸ The Civil Rights Act of 1964 was filibustered for 60 working days, including seven Saturdays, before cloture was finally invoked 71 to 29 — the first successful civil rights cloture vote ever.⁹ The bill passed nine days later.¹⁰

How Effective at Forcing Compromise

Supporters argue the 60-vote requirement produces broader, more durable coalitions than a bare majority would. Two recent bills give that argument its strongest evidence.

The 2022 Bipartisan Safer Communities Act followed the mass shootings in Buffalo and Uvalde. A group of senators including Chris Murphy, John Cornyn, Kyrsten Sinema, and Thom Tillis negotiated a package that could clear cloture. Advocates had wanted an assault weapons ban, but there were not 60 votes for one. Instead, negotiators wrote narrower provisions: enhanced background checks for buyers under 21, funding for state red-flag laws, closure of the domestic-violence “boyfriend loophole,” and stronger gun-trafficking penalties. The bill passed 65 to 33 and was the first significant federal gun legislation in 30 years.¹¹¹²

The 2021 Infrastructure Investment and Jobs Act followed a similar pattern. A $1.2 trillion package with $550 billion in new spending on roads, bridges, broadband, and rail was negotiated by the Biden administration and a bipartisan group of 21 senators, then passed the Senate 69 to 30.¹³¹⁴ The need for 60 votes shaped the negotiation.

That is the compromise-forcing mechanism working. It is less clear how often it works. For every Bipartisan Safer Communities Act, there is a background-checks bill that got 54 votes and died. And the compromise version is often visibly narrower than what a majority wanted — a working mechanism from the defenders’ view, a stripping mechanism from the critics’.

The Gridlock Story Is More Contested Than It Looks

The intuitive claim — kill the filibuster and the Senate will pass more of the majority’s agenda — is not settled among scholars. A primer from the University of Chicago’s Center for Effective Government found “little evidence” that eliminating the filibuster would significantly improve Senate productivity. The primary reason Senate majorities fail to enact their agendas, the primer argued, is internal disagreement within the majority party, not minority obstruction.¹⁵

Keith Krehbiel’s “pivotal politics” theory models how the filibuster and the presidential veto create a policy zone neither party can break through without a large coalition. Research by Thomas Gray and Jeffery Jenkins refined the theory and found the gridlock effect is strongest on ideologically charged legislation; nonideological bills actually pass more easily when the gridlock interval is wide.¹⁶ Other scholars argue partisan dynamics and presidential leadership matter more than the 60-vote threshold alone.¹⁷

Sarah Binder, one of the researchers whose earlier work catalogued filibustered bills, has noted an important contextual shift. In a more centrist Senate, the 60th vote sat ideologically close to the majority. In today’s polarized Senate, the distance between the 51st and 60th vote is much greater, making the filibuster a more potent barrier than it was a generation ago.⁵ Whatever the filibuster used to do to majority agendas, it is doing more of it now.

Where the Filibuster No Longer Applies

The 60-vote requirement is not universal, and a reader thinking about what the filibuster still stops needs to know what has been carved out. More than 160 exceptions have been created since 1969.¹⁸ Three matter most.

Budget reconciliation lets bills adjusting taxes and spending pass with a simple majority. This is the route through which sweeping tax legislation and major parts of the Affordable Care Act became law without needing 60 votes.

Nominations were carved out in two steps. In 2013, the Democratic majority used the “nuclear option” to let executive branch nominees and lower-court judges be confirmed by simple majority. In 2017, the Republican majority extended that to Supreme Court nominations.¹⁹

Fast-track trade agreements, military base closures, and certain arms sales are also exempt.¹⁸

The cumulative effect is uneven. The filibuster remains strong on general legislation but not on nominations or fiscal policy. Critics argue this patchwork has pushed too much consequential lawmaking into reconciliation, which was not designed for sweeping policy changes.¹⁸ Gridlock on ordinary legislation has also pushed presidents to rely more heavily on executive orders, which the next administration can reverse.⁸

Talking Filibusters: Symbolism That Sometimes Works

Individual senators still occasionally return to the floor for marathon speeches. These are usually symbolic, but not always empty.

In March 2013, Senator Rand Paul spoke for more than 13 hours to delay CIA nominee John Brennan’s confirmation, demanding an answer on whether the president could use armed drones against American citizens on U.S. soil.²⁰ The next day, Attorney General Eric Holder sent Paul a letter answering with a single word: “No.”²¹ Brennan was confirmed anyway.

In June 2016, after the Orlando nightclub shooting, Senator Chris Murphy held the floor nearly 15 hours, joined by 40 Democrats. He secured a commitment to hold votes on banning individuals on terrorism watch lists from buying firearms and expanding background checks. Neither measure passed.²²²³

In April 2025, Senator Cory Booker delivered a 25-hour, 5-minute floor speech protesting Trump administration policies on education, Social Security, and Medicaid — the longest in Senate history.²⁴ It drew significant attention and no legislative changes.²⁵

The pattern: a talking filibuster can extract an answer, a scheduled vote, or public attention. It rarely changes an outcome the votes were not already there to produce.

Why the Filibuster Endures

Only 51 senators are needed to change the rules at any time, so the filibuster’s persistence, as the UChicago primer put it, reflects the “tacit consent of the Senate majority.” Successive majorities have chosen to keep the rule, adding carve-outs rather than abolishing it. That suggests senators in the majority repeatedly calculate that the filibuster serves their interests — by forcing bipartisan cover for hard votes, or by shielding moderates from pressure by their own party’s base.¹⁵

That calculation held through late 2025. During a government shutdown, President Trump pressed Senate Republicans to invoke the nuclear option and eliminate the legislative filibuster. Majority Leader John Thune said his position was “unchanged,” and Republican senators including John Barrasso and John Curtis publicly opposed elimination.²⁶ House Speaker Mike Johnson called the filibuster a “safeguard in the Senate.”²⁷ The 60-vote legislative filibuster is intact.

So: are filibusters effective? At their primary function, blocking bills a minority opposes, yes — measurably, historically, and increasingly. At forcing compromise, sometimes, when the political conditions independently support a deal. At producing coherent governance in a polarized Senate, the evidence is thinner, and much of what the Senate now accomplishes it accomplishes by working around the filibuster rather than through it.

1
U.S. Senate. Filibusters and Cloture
2
PBS NewsHour. What Is the Filibuster
3
Constitution Center. Filibustering in the Modern Senate
4
U.S. Senate. Senate Action on Cloture Motions
5
Niskanen Center. The Resilience of the Filibuster and Its Myths
6
Center for American Progress. The Impact of the Filibuster on Federal Policymaking
7
Brennan Center for Justice. The Case Against the Filibuster
8
Citizens for Responsibility and Ethics in Washington. The Filibuster Must Go
9
U.S. Senate. Civil Rights Act of 1964
10
National Archives. Civil Rights Act
11
PBS NewsHour. Senate Passes Bipartisan Gun Violence Bill
12
Center for American Progress. The Bipartisan Safer Communities Act, One Year Later
13
U.S. Senate. Roll Call Vote 314, 117th Congress
14
New York Times. Senate Infrastructure Legislation
15
UChicago Center for Effective Government. Filibuster Reform
16
Cambridge University Press. Pivotal Politics and the Ideological Content of Landmark Laws
17
JSTOR. When Pivotal Politics Meets Partisan Politics
18
Brennan Center for Justice. The Filibuster, Explained
19
Brookings Institution. What Is the Senate Filibuster
20
Politico. Rand Paul Filibuster
21
NPR. Sen. Paul Ends His Filibuster
22
Roll Call. Filibuster Over, Senate Will Take Up Two Gun Control Measures
23
CT Mirror. Murphy Filibusters on Gun Safety
24
Office of Senator Cory Booker. Senator Booker’s Marathon Speech
25
The 19th. Cory Booker Trump Floor Speech
26
ABC News. Senate Filibuster: Trump Calls on GOP to Eliminate
27
Federal News Network. Trump Says Senate Should Scrap the Filibuster