To observe the moribund Democrats and gleeful Republicans last week in the wake of Scott Brown's Massachusetts miracle, one would think that the number of Democrats in the Senate had already dipped to 49, rather than 59. And that's actually not too far off base. As the Village Voice put it: "Scott Brown Wins Mass. Race, Giving GOP 41-59 Majority in the Senate." Or as a friend quipped, 60 is the new 50.

That's because of the filibuster, which allows 41 members to prevent a final vote on almost any piece of legislation. Mere majority support is insufficient to pass a bill; you must have a supermajority. Contemporary politics and recollections of famous past filibusters—whether the heroic Jimmy Stewart in 1939's Mr. Smith Goes to Washington or the villainous Strom Thurmond in 1957's civil rights debate—would lead one to believe that this was always the case. But that is not so.

In fact, the use of the filibuster has undergone a radical shift, from protecting the party out of power to creating a tyranny of the minority.

According to Barbara Sinclair, a political scientist at UCLA who has tabulated such statistics, there was an average of one filibuster per Congress during the 1950s. These were the Mr. Smith- and Strom-style filibusters of popular imagination: a lone senator or small group tying up the floor, talking endlessly. And they bear little resemblance to the modern filibuster, which is all talk or no talk at all, depending upon how you view it. That's because in 1964, the Senate adopted a two-track method of debating legislation. Instead of the chamber grinding to a halt during a filibuster, other work could go on. And then in 1975, the threshold for breaking a filibuster was lowered from 67 to 60 votes.

Filibusters became both less disruptive and more easily managed, and by the mid-1980s, there were almost 17 per Congress. Filibustering took on a new definition. No longer was it talking a bill to death; it was merely an inability to muster 60 votes to end debate.

Then the practice really took off. By the time Bill Clinton entered office, party leaders had realized that it could be used as a partisan political tool, and filibustering legislation became commonplace. "Republicans kind of realized that they can make a really concerted use of extended debate to deprive Democrats of victories," Sinclair says. The election of 1994 only reinforced the strategy of no. Why help the majority pass legislation when you can stall until voters, frustrated with gridlock, throw the other side out? Once out of power, Democrats went to school on the GOP delaying tactics.

The parties themselves were becoming ideologically homogenous as liberal GOPers and conservative Democrats disappeared. Historically, the filibuster "was liberals versus conservatives, but never Democrats versus Republicans," explains Donald Ritchie, the Senate historian.

By the end of George W. Bush's second term, there were an astonishing 52 filibusters per Congress. That's a 52-fold increase. Or to slice the data a different way, 8 percent of major legislation in the 1960s was subjected to delaying tactics like filibusters, according to Sinclair. By the last two years of Bush's term, a mind-boggling 70 percent of major bills were subjected to such tactics.

The filibuster is out of control. And it's dangerous. As President Obama argued in a year-end interview with PBS, "If used prudently, then I don't think it's harmful for democracy. It's not being used prudently right now." What to do about it? The options are unhappily slim.

Democrats could exercise the so-called nuclear option, changing the Senate rules to essentially ban the filibuster. This is a non-starter. Few senators would agree to such a diminishment of their individual power, and it would also be shortsighted. Democrats will be out of power again and would miss the filibuster were it gone. But perhaps the time has come to consider a shift from 60 votes to, say, 55.

Another option is to take the filibuster old school. Kill the two-track method, and force all-night talkathons again. The problem, according to Ritchie, is that it's self-defeating. A small group of senators can sustain a filibuster in shifts, but because of parliamentary rules, all those trying to break it have to be on hand. "Jimmy Stewart made it romantic," Ritchie says, "but it actually doesn't wear down Jimmy Stewart as much as all the other senators who have to be there."

Maybe he's right. But maybe in a 24-hour media environment, the spectacle of watching a GOP minority talking a popular piece of legislation to death would generate a public backlash.

The first step to reining back in the filibuster might just be public education: Make people understand that it has gotten out of hand and is being abused. "If this pattern continues," the president told PBS, "you're going to see an inability on the part of America to deal with big problems in a very competitive world. ... We're going to have to return to some sense that governance is more important than politics inside the Senate."

He could repeat that message, beginning with the State of the Union address. It may not be enough, but it's a start.

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