That's because of the filibuster, the now widely-used practice of keeping debate going in perpetuity on a bill in order to kill it. Under Senate rules, the only way to defeat a filibuster is to get 60 votes – nine more than you would need simply to pass the measure.
The filibuster is a self-imposed Senate rule, and, as James Fallows details here, it hasn't always been such a factor in Senate business. Filibustering was rare for most of the Senate's first two centuries, though perhaps more effective; for much of that period, backers needed 67 votes to overcome a filibuster.
The Senate changed the rules in 1975, so that it would only take 60 votes to overcome a filibuster. Not too long after that – beginning roughly around the time Bill Clinton came into office – filibustering went from a rare maneuver to common practice. It's been particularly popular among Senate Republicans in the most recent Congress, as Norman Ornstein illustrates here.
"Republicans have invoked filibusters or used other delaying tactics on controversial issues like Medicare prescription drugs, the war in Iraq, and domestic surveillance—and on non-controversial issues like ethics reform and electronic campaign disclosure," he notes.
Now there is growing momentum to change the filibuster rule – which, opponents are quick to point out, is not written into the Constitution. Earlier this month, Sen. Tom Harkin (D-Iowa) told reporters he is considering re-introducing a bill to significantly soften the power of the filibuster.
Harkin first introduced his bill in 1995 – with Connecticut independent Sen. Joe Lieberman as a co-sponsor. Lieberman, of course, recently leveraged the threat of not voting with Democrats in order to get major concessions on the health care bill, something he would not have been able to do without the current filibuster rules.
Harkin's bill keeps the 60-vote rule for the first vote but lessens it with each subsequent vote – after a week of debate, he suggested, the number of votes needed to defeat a filibuster would drop to 57. That process would continue until the simple majority of 51 votes was needed to end debate.
New York Times columnist Paul Krugman is among those calling for an end to the current filibuster rule, which he suggested in a column effectively paralyzes a Congress that needs to deal with major issues like climate change, financial reform and the budget deficit.
"Nobody should meddle lightly with long-established parliamentary procedure," he writes. "But our current situation is unprecedented: America is caught between severe problems that must be addressed and a minority party determined to block action on every front."
Changing the rule would not be easy no matter who is in power, since the minority party would fiercely object – and, indeed, likely filibuster the effort. But since Democrats currently have a so-called "supermajority," a caucus made up of 60 votes, it's not inconceivable that they could do so. And that would mean they would have a far easier time passing their legislative agenda than they do under the current system.
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