Final answer:
The 2013 change to the Senate filibuster rules reduced the cloture requirement from 60 votes to a simple majority of 51 votes for executive branch and federal judicial nominations, excluding those for the Supreme Court. This was part of a larger historical evolution of the filibuster from extended debate to procedural form, reflecting increased partisanship within the Senate.
Step-by-step explanation:
In 2013, significant changes were made to Senate filibuster rules concerning the blocking of presidential appointees. Previously, it was common for senators to use the filibuster to prolong debate indefinitely and thus prevent a vote on a nominee. The modification reduced the number of votes needed for cloture, effectively the closing of debate, from three-fifths (60 votes) to a simple majority (51 votes) for all executive branch nominees and federal judicial appointees, except those for the Supreme Court. This alteration was sometimes referred to as the "nuclear option" because of its significant impact on Senate procedures. These changes were important in the context of an increasingly partisan Senate, where such tactics were used to delay or prevent nominations not due to the qualifications of the nominee, but as a form of political obstruction.
Historical Context of the Filibuster
The filibuster is a Senate tradition allowing unlimited debate on a bill; a tool historically used to stall or block legislation and nominations. Over time, this has evolved from extended physical debate to a procedural form, where indicating the intention to filibuster is sufficient. To end a filibuster, a cloture vote with a supermajority was typically required. This rule has been adjusted over the years, including the key change in 2013, tailored specifically for non-Supreme Court nominations within the executive branch and federal courts.