In 1917, during the presidency of Woodrow Wilson, the Senate adopted a rule permitting a “cloture vote,” which provided that a vote of two thirds of the body could end a filibuster. A two-thirds vote on a matter before the Senate typically represents close to a national consensus, and by placing this rule on the books, it was assured that a small minority could not defeat the overwhelming will of the American people. Nonetheless, the Senate did not invoke the provision even once from 1927 until the early 1960s. Senators were reluctant to vote for cloture because they wanted to keep the right for themselves, and did not wish to incur the wrath of a colleague by imposing a cloture vote on another senator or group of senators who felt so strongly about a matter that they were willing to mount a filibuster. Jimmy Stewart’s 1939 portrayal of a heroic use of the filibuster in
For decades before the advent of Mansfield’s system, in order to conduct a filibuster a senator had to be recognized by the presiding officer and then had to maintain the floor by talking. Because one man (or woman) can talk for only so long without sitting, eating, sleeping, or addressing other human necessities, the senator running it was permitted to yield to a colleague to continue it, thus operating like a tag team. Groups of senators would agree in advance to relieve one another to prevent loss of the floor and to make it possible to continue round-the-clock. They would sleep on sofas in the Senate cloakroom; some even wore a device known to long-distance bus drivers as a motorman’s pal, enabling them to relieve themselves without leaving the Senate floor. Thus, whenever there was a filibuster, all other Senate business came to a halt until they either got the unwanted proposal removed from the Senate’s agenda or a cloture vote ended it.
Mansfield’s proposal changed all this. The Senate, by long tradition a highly collegial body, does most all of its business, of necessity, by unanimous consent. Under Mansfield’s “two-track” system, the Senate agreed, by unanimous consent, to spend its mornings on the matter being filibustered, and afternoons on other business. Professors Catherine Fisk and Erwin Chemerinsky pointed out in a study that this system worked for everyone. On the one hand, the two-track system strengthened the ability of the majority to withstand a filibuster by enabling it to conduct other business. On the other hand, it made it easier for the minority, which no longer had to hold the floor continuously to prevent something less than a supermajority from cutting it off. In time, the mere prospect of a filibuster became enough to block consideration of a given matter. Based on successive changes of the Senate rules, the supermajority needed for a cloture vote was reduced to a vote by sixty senators. Thus, when a senator informs the leadership of plans to filibuster—and the leadership knows that he or she has the support of at least sixty senators and, therefore, the ability to invoke cloture and override the threatened filibuster—the matter will not even go to the floor for a vote. The modern filibuster has therefore become silent, since its mere threat results in stopping a debate in its tracks.