In 2013, the Senate reduced the cloture threshold for confirming federal judicial nominees to a simple 51-vote majority.
Notes on verification
Multiple independent contemporaneous and retrospective sources (ABA, Washington Post, CBS, Heritage Foundation) consistently confirm the exact date, vote count (52-48), and mechanism of the 2013 'nuclear option' rule change.
Sources
- Filibuster, cloture: US Senate rules featured in abortion debate | Politics News | Al Jazeera (aljazeera.com)
- https://www.washingtonpost.com/politics/senate-poised-to-limit-filibusters-in-party-line-vote-that-would-alter-centuries-of-precedent/2013/11/21/d065cfe8-52b6-11e3-9fe0-fd2ca728e67c_story.html (washingtonpost.com)
- https://www.heritage.org/political-process/commentary/5-years-after-going-nuclear-democrats-have-reaped-what-they-sowed (heritage.org)
- https://www.americanbar.org/advocacy/governmental_legislative_work/publications/governmental_affairs_periodicals/washingtonletter/2013/november/filibuster/ (americanbar.org)
- https://cbsnews.com/news/reid-invokes-nuclear-option-to-get-obama-nominees-approved (cbsnews.com)