The rules are the rules until they are changed. That explains the "nuclear option", so called because it represents the biggest, baddest weapon in the Senate arsenal. Before 2013 it took three fifths (60) votes in the Senate to end debate on a bill or nomination and two thirds (67) votes to end debate on changing a senate rule. The nuclear option lets the Senate change the the rules to allow for a simple majority vote of 51 to override a rule or precedent.
This practice of changing the rules has been employed by both parties. Most recently and most famously by Harry Reid to block a Republican filibuster of executive branch nominees. A filibusters is essentially a stalling tactic.
Whether or not you agree with filibusters, nuclear options, 60 votes or 51 votes the trend to cap or eliminate discussion and to call for cloture (stopping discussion) has had a marked increase. From a fairly flat trend starting in 1917 to the late 60s, then rising steadily to 2004 and spiking in 2008-2010. The bottom line? We have a Congress that is totally unable to solve any sort of problems or make any sort of decisions.
