What is a filibuster?
It’s a procedure used in the U.S. Senate to prevent legislation or nominations from ever getting past the talking stage. Senate rules allow members to debate a matter indefinitely, unless at least 60 out of 100 senators vote to cut off debate, or “invoke cloture.” The debate doesn’t even have to take place. Senators can simply indicate that they’ll oppose a cloture vote, and if they have 41 votes, supporters of the bill or nomination will often pull it before the debate even begins. In other words, the mere threat of a filibuster is now enough to derail a bill. Just last week, President Obama withdrew the nomination of his choice for a slot on the National Labor Relations Board because Democrats, who now have a 59–41 majority in the chamber, could not muster the 60 votes they needed to cut off “debate.” Last fall, Nebraska Sen. Ben Nelson, a Democrat, refused to vote for cloture on the Democrats’ health-care-reform measure until it was modified to add Medicaid benefits for his home state—a deal critics quickly dubbed the “cornhusker kickback.”

Has the filibuster always worked this way?
No. It used to be far more entertaining—or at least more obvious. Until a rule change was enacted in 1975, senators actually had to take to the floor and talk, and talk, and talk—like the iconic scene in Mr. Smith Goes to Washington, in which Jimmy Stewart’s character recites the Constitution until he collapses from exhaustion. In 1957, South Carolina Sen. Strom Thurmond temporarily succeeded in stalling a civil-rights bill by speaking uninterrupted for a record 24 hours, 18 minutes. He’d prepared by spending hours in the Senate steam room, dehydrating himself so he wouldn’t need a bathroom break. Back in 1908, Wisconsin Sen. Robert La Follette so exasperated his colleagues by filibustering a currency bill that somebody slipped him a glass of ptomaine-laced milk. La Follette had to leave the floor to vomit, bringing his filibuster to an ignominious conclusion. Such undignified scenes eventually helped persuade senators to implement the more low-key filibuster in effect today.

Don’t filibusters subvert majority rule?
That’s the point. The word “filibuster” is a corruption of the Dutch word for the 19th-century pirates who plied the Caribbean, capturing entire islands with just a handful of men. Like those pirates, a few determined senators can take a bill hostage, even if the bill enjoys wide popular support. And while that might seem unfair—and even undemocratic—most legal scholars agree it’s permitted by Article 1 of the Constitution, which gives both houses the right to make their own rules. Senate rules have always encouraged prolonged debate, reflecting George Washington’s view of the Senate as a “saucer” where the superheated passions of the moment can cool. “The filibuster is frustrating, literally and intentionally,” says Washington Post columnist Ruth Marcus. But “it is wonderful if you are trying to block something bad from happening.”

How often is the tactic used?
Until the 1970s, filibusters were generally reserved for momentous bills, like declarations of war or civil-rights measures. But during the George W. Bush administration, Democrats used the filibuster threat to block several of Bush’s more conservative judicial nominations. And since the Republicans lost their Senate majority in 2006, they have returned the favor, to the point where filibusters are now routine. In the 1975–76 session, there were 39 cloture votes; by the 2007–08 session, there were 139, and that record is likely to be shattered by the current Senate. “The Senate is set up culturally not to act on anything quickly, and that’s a good thing,” says congressional historian Norman Ornstein. “But there can be too much of a good thing.”

Can’t Democrats just kill the filibuster?
Not easily. Senate rule changes require the backing of at least 67 senators. But some Democrats are now contemplating an alternative way to kill the filibuster once and for all, using a tactic that’s been dubbed the “nuclear option.” It involves a complicated series of parliamentary maneuvers that would end with Vice President Joe Biden, in his capacity as presiding officer of the Senate, declaring the filibuster to be unconstitutional, because it usurps his power to break Senate deadlocks. The move would almost certainly provoke a constitutional crisis, but at least some Democrats want to give it a try. Former party Chairman Howard Dean admits that Democrats would miss the filibuster when they’re once again in the minority. But “for the good of the country,” he says, “we probably have to eliminate it.”

What’s good for the goose …
In January, Vice President Joe Biden, formerly a longtime senator from Delaware, gave a rousing speech denouncing Republican filibusters. “I have never seen the Constitution stood on its head as they’ve done,” he said. “This is the first time every single solitary decision has required 60 senators.” But he’d sounded quite a different note in 2005, when he and his Democratic colleagues were frequently resorting to the filibuster to bottle up President Bush’s judicial picks. “At its core,” Biden said at the time, “the filibuster is not about stopping a bill, it’s about compromise and moderation.” But hypocrisy over the filibuster is a bipartisan affair. Back when Biden was defending the filibuster, Alabama Republican Sen. Jeff Sessions bawled out his Democratic colleagues for their “unprecedented” and “obstructionist” tactics. Today, Sessions defends the filibuster, saying that his party “cannot acquiesce to philosophy that says Democratic presidents can get their judges confirmed with 50 votes.” The shifting stances of both sides bear out a point about the filibuster made by Senate historian Donald Ritchie. “It’s really not a Republican Party position and a Democratic Party position,” he says. “It’s a minority-party position and a majority-party position.”