The New York Times has the all-important filibuster today that includes one somewhat misleading quote:

In 1975, the Senate cut the required vote for cloture to three-fifths, or 60 senators, instead of 67.

At about the same time, the Senate created a two-track process that allows senators to block action on a piece of legislation merely by invoking the right to filibuster, without actually having to stand before the chamber and drone endlessly on. Meanwhile, the Senate can take up other business.

The measure, intended to promote efficiency, inadvertently encouraged filibusters by making them painless, said Julian Zelizer, a historian of Congress at Boston University. “The filibuster exploded, and became a normal tool of political combat,” he said. In 1995, he noted, almost 44 percent of all major legislation considered by the Senate was delayed by a filibuster or the threat of one.

Professor Zelizer calls the filibuster a relic, stained by its use to block civil-rights legislation. But in the polarized Congress of today, he said, “this is one way to check the partisan domination we have.” Because it forces the majority to negotiate with the other party, the filibuster “is one of the few forces pushing toward the center,” Professor Zelizer said.

It is true that the filibuster weakens the power of the majority party in the Senate. But it doesn’t necessarily push policy toward the center, as Keith Khrebiel’s Pivotal Politics illustrates. In some cases, policies are modified to win the support of senators from the opposition party and get to the required 60 votes, and the bill that goes through is closer to the center than it otherwise would have been. But in other cases, Congress can actually be prevented from moving policy closer to the center by a successful filibuster, as it was in 1998 when McCain-Feingold was defeated. Another example is the Clinton health care plan in 1994. Most Americans preferred health care reform, but rather than work out a compromise that would have moved policy closer to the center, the whole plan was killed by Republicans wielding a potential Senate filibuster. The story is not so simple – it depends on the configuration of the different branches of government, and where the status quo policy is on the ideological spectrum.