How a Senate Loophole Became a 60-Vote Veto

When Aaron Burr finished his term as vice president in 1805, he gave the Senate a farewell speech full of unsolicited advice on rules cleanup. Among his suggestions: drop a procedure called the previous question motion, which the Senate had used roughly twice in fifteen years and which let a majority cut off debate. The Senate took the advice in 1806. By accident, it had eliminated its only tool for ending debate by majority vote.

For decades nothing happened. The first true filibuster — endless speech to block a vote — came in 1837 over a Whig effort to censure Andrew Jackson. By the late nineteenth century the tactic was common enough to crowd Senate calendars. It took a war to provoke a response. In 1917, after pacifist senators talked President Woodrow Wilson's armed-merchant-ships bill to death, Wilson denounced the practice and the Senate adopted Rule XXII, which let two-thirds of senators vote cloture and end debate.

The two-thirds threshold dropped to three-fifths — 60 of 100 — in 1975. Then the Senate carved exceptions. In 2013 Democrats removed the 60-vote requirement for most executive nominations and lower-court judges; in 2017 Republicans extended that to Supreme Court justices. Budget reconciliation, also a majority-vote process, has expanded steadily as the workaround of choice for major legislation.

The modern filibuster does not require talking. Since the 1970s, a senator can simply signal an objection, and the chamber moves on unless leadership can muster 60 votes. That makes it cheap to use and hard to break. A loophole left open by Burr's housekeeping has become the most consequential procedural rule in American legislating.