Although the term filibuster was first applied to the practice in the 1850s, the opportunity for unlimited Senate debate dates from the creation of the Republic. Indeed, in the 19th century—especially the 1830s and 1840s—great Senate oratory was something of a spectator sport.

The first restriction against the concept came in 1917. Just days before the end of the congressional session, Woodrow Wilson introduced a measure to allow the government to arm U.S. merchant ships, to protect them against German submarines. The House easily passed the"armed ship bill," but it floundered in the Senate. Around 15 left-wing senators opposed the measure, on the grounds that it would invariably drag the United States into the European conflict. Organized by Robert La Follette, George Norris, and Foreign Relations Committee chairman William Stone, they decided to filibuster the bill until the session ended, which would effectively kill the measure.

The bill's supporters weren't exactly well-organized—they wound up consuming more time in debate than did the critics. Wilson, however, fumed that"a little group of willful men, representing no opinion but their own, have rendered the great government of the United States helpless and contemptible. (The President than armed the ships by executive order.) A public outcry led the Senate to adopt Rule 22, which allowed cloture by a vote of two-thirds.

After the Wilson years, cloture would not again be imposed until 1962—and then to terminate a liberal filibuster against John Kennedy's commercial satellite proposal (which created a public-private partnership with AT&T). But Southerners' ability to weaken or kill civil rights measures through filibuster came to an end in 1964, when the Senate successfully imposed cloture on the 1964 Civil Rights Act.

Through the 1960s, filibusters were just that: talk-a-thons on the Senate floor. But after the Senate changed its rules in the early 1970s to allow cloture with 60 rather than 67 votes, the threat of a filibuster became a parliamentary tactic—used by the minority to demand a supermajority before significant bills would pass.

In the last 15 years, the use of the filibuster expanded dramatically: a turning point was the 1993-1994 Congress, when the Bob Dole-led Republicans used the tactic liberally, requiring 47 cloture votes (as opposed to just 24 in the previous Congress). When the Democrats fell back into the minority after 1994, they imitated Dole's tactics, and the threat of filibusters remained stable throughout the 1990s.

A recent chart prepared by the left-leaning Campaign for America's Future, however, indicates a stunning change in the current Congress: through December 18, more cloture votes have occurred in this Senate session than in any full congressional session in U.S. history. The projected total of cloture votes for the full session, at the current rate, is 134. The previous high was 61.

This change amounts to a constitutional amendment by parliamentary tactic: Senate Republicans effectively have required a supermajority for virtually any contested bill. (Senate Republicans two years ago called for eliminating the filibuster, but only on judicial nominees.) It's hard to motivate people behind a"good-government" cause. But if members of both parties feel that a super-majority should be required to pass any Senate measure, they should be forthright about it, and propose a constitutional amendment. In the interim, Senate majority leader Harry Reid (and Senate minority leader Mitch McConnell, if the GOP reclaims the majority in 2008) should at the very least return to the pre-1974 practice, and force those intent on filibustering to actually consume time on the floor actually filibustering.