After a series of filibusters in the 1960s over civil rights legislation, the Senate put a «two - track system» into place in the early 1970s under the leadership of Majority Leader Mike Mansfield and Majority Whip Robert Byrd. (politics.stackexchange.com)
The Moderates get turned off by the Party Platform and decide to return to their parent's Democratic Party roots in enough districts to return control of Congress to the Democrats, and eliminate the threat of Republican Filibuster in the Senate. (religion.blogs.cnn.com)
threatened to change the Senate rules in order to break Democratic filibusters on a series of federal judge appointments put forward by President Bush. (voices.washingtonpost.com)