Final answer:
A filibuster in the U.S. Senate can be stopped when three-fifths of the Senate, or 60 Senators, vote for cloture, which is a motion to end debate on a bill.
Step-by-step explanation:
A filibuster can be stopped when three-fifths of the Senate votes for cloture. This procedural rule allows the Senate to limit the time spent debating a bill and eventually brings it to a vote, effectively overcoming the filibuster. A filibuster is a strategic action where a Senator or group of Senators can extend debate over proposed legislation to delay or prevent a vote. In 1975, the number of votes required for cloture was reduced from a two-thirds majority to a three-fifths majority, which equates to 60 votes in the 100-member Senate. This change enabled the Senate to more easily break filibusters compared to the previous two-thirds requirement, though it still mandates a supermajority.
The Senate can also use the budget reconciliation process, which is not subject to filibuster, to pass significant pieces of legislation, such as the Affordable Care Act and the Tax Cuts and Jobs Act. However, for most non-budgetary legislation, the requirement for cloture means a minority can hold significant power to obstruct legislation by invoking a filibuster, which only ends when a supermajority votes to cease debate and move forward.