The Filibuster
A Senate procedure that began as a delay tactic and became an effective veto on any legislation that can't find 60 votes — a threshold the Constitution never requires.
The short version
- The filibuster is not in the Constitution — it is a Senate rule that now effectively requires 60 of 100 votes to pass any legislation, rather than the simple majority the Constitution implies.
- The modern filibuster requires no speaking. Senators signal intent and the burden shifts to the majority to find 60 votes; the talking marathon is a myth of the current system.
- The filibuster has been used most prominently in American history to block civil rights legislation — anti-lynching bills, voting rights, and the 1964 Civil Rights Act all required fighting through it.
- The Senate has already eliminated the filibuster for executive nominations and Supreme Court confirmations; the legislative filibuster is the last remaining version, and the one most consequential for ordinary governance.
What it is
The filibuster is a parliamentary tactic that exploits the Senate's tradition of unlimited debate to delay or prevent a vote on legislation. The word itself derives from a Dutch and Spanish term for pirate — 'vrijbuiter' and 'filibustero' — reflecting the obstructive, opportunistic nature of the maneuver. In its original form, a senator who opposed a bill could simply refuse to stop talking, holding the floor indefinitely to prevent a vote. The record belongs to Senator Strom Thurmond, who spoke for 24 hours and 18 minutes in opposition to the Civil Rights Act of 1957 — a performance that failed to kill the bill but delayed and weakened it. For most of the 19th and early 20th centuries, the filibuster was rare, labor-intensive, and generally considered a last resort.
The procedural history of the modern filibuster runs through two key reforms. The first came in 1917, when President Woodrow Wilson, frustrated by a small group of senators blocking his proposal to arm merchant ships ahead of U.S. entry into World War I, pressured the Senate to adopt a cloture rule — Rule XXII — allowing a two-thirds majority to end debate. This gave the filibuster a formal counter but required a supermajority to invoke it. In 1975, the Senate reduced the cloture threshold from two-thirds to three-fifths (60 votes) — the current threshold. But 1975 also produced the change that mattered more: the adoption of the 'two-track' system, which allowed the Senate to proceed with other business while a cloture process was pending. Before tracking, a filibuster required occupying the Senate floor. After tracking, a senator needed only to notify the majority leader of intent to filibuster, and the burden shifted to the majority to muster 60 votes. The talking filibuster became a paperwork filibuster.
The modern filibuster, operating since roughly the mid-1970s and hardening to its current form through the 2000s, requires almost no effort from the objecting party. A senator — or merely a senator's staff — signals that cloture would be required, and the majority leader either schedules a cloture vote (requiring two days of procedural time and 60 votes to succeed) or simply moves on. The threat alone is sufficient; the vote is often not even held. The result is that in the modern Senate, the effective threshold for passing legislation is 60 votes, not 51. This is not a constitutional requirement. The Constitution specifies supermajority requirements for exactly six categories of Senate action: ratifying treaties, overriding vetoes, convicting in impeachment proceedings, expelling members, overriding a presidential veto, and proposing constitutional amendments. On everything else, the Framers' assumption was simple majority.
The filibuster has been eroded piecemeal. In 2013, Senate Majority Leader Harry Reid invoked what became known as the 'nuclear option' — changing Senate rules by simple majority vote — to eliminate the filibuster for executive branch nominations and federal judicial nominations below the Supreme Court level, after Republicans had blocked an unprecedented number of Obama's nominees. In 2017, Senate Majority Leader Mitch McConnell extended the nuclear option to Supreme Court nominations, enabling Neil Gorsuch's confirmation after Merrick Garland's nomination had been held in limbo for nearly a year without a hearing. The legislative filibuster remains. The practical result is that the most politically consequential decisions — who sits on federal courts and the Cabinet — are now decided by majority vote, while the policies those officials implement are constrained by a 60-vote threshold.
Why it matters
The filibuster's history is inseparable from the history of American racial politics. For the first half of the 20th century, it was the primary legislative tool used by Southern Democrats to block federal civil rights legislation. Between 1917 and 1964, the Senate considered at least 70 anti-lynching bills; the filibuster killed every one of them. The 1964 Civil Rights Act faced a 60-day filibuster — the longest in Senate history — before cloture was finally invoked with bipartisan support. The Voting Rights Act of 1965 passed after another filibuster attempt was defeated. This history is not incidental to the filibuster's legacy; it is its defining use. The procedural tool's longest and most consequential application was the systematic obstruction of racial equality legislation for half a century.
In the contemporary Senate, the filibuster blocks legislation that commands majority support in the chamber and majority support in the country. Since 2010, the filibuster has been used to block or credibly threaten to block: the DISCLOSE Act (campaign finance disclosure), the John Lewis Voting Rights Advancement Act, universal background check legislation after mass shootings, the Paycheck Fairness Act, immigration reform bills with bipartisan support, minimum wage increases, and climate legislation. In each case, a majority of senators supported the bill and a majority of the public supported the bill. The 60-vote threshold prevented a vote. The argument that the filibuster protects 'minority rights' technically refers to the Senate minority — not racial, geographic, or any other demographic minority — and in the current partisan alignment, the minority it most consistently protects is the partisan minority.
The Senate's structure already dramatically over-represents small states: Wyoming (population ~580,000) and California (population ~39 million) each have two senators. This is a feature of the constitutional design, reflecting the Great Compromise of 1787, and cannot be changed without unanimous state consent. The filibuster compounds this existing malapportionment: a 60-vote cloture threshold applied to a chamber that already over-represents less populous, more rural, whiter states requires winning senators who collectively represent a significantly larger share of the national population than a simple majority would require. Political scientists have calculated that the senators needed to break a filibuster — 40 senators representing their states — could represent as little as 11% of the U.S. population.
The reform debate reflects genuine disagreement about the Senate's institutional purpose. Defenders argue that the 60-vote threshold promotes deliberation, forces bipartisan compromise, and prevents one-party majorities from making rapid and reversible changes to fundamental law. Critics respond that the deliberation argument is undermined by the fact that the modern filibuster involves no deliberation — senators don't have to speak, engage, or even be present. The compromise argument fails when one party decides to oppose legislation categorically rather than negotiate. And the protection-against-reversibility argument applies equally to popular policies that a subsequent majority would reverse, a case that cuts in multiple directions. The filibuster's current form — effortless, non-deliberative, and used routinely rather than rarely — bears little resemblance to the institutional design its defenders invoke.