From Monday's Washington Post:
Increasingly, the White House appears to favor having the House pass a version of the measure that cleared the Senate with 60 votes in December. The Senate would then pass changes to the bill to satisfy some demands of House Democrats. That Senate vote would take place under a parliamentary procedure known as reconciliation, which requires 51 votes rather than 60.
If this is President Barack Obama's path to health care reform—and it seems like his only option at this point (though I'm told some in the White House have not given up on the idea of a bipartisan deal)—he won't need 51 votes in the Senate. He will need 50. On a 50-50 tie, Vice President Joe Biden will get to be the decider. That would, no doubt, prompt futher howls from Republicans who already are trying to denigrate reconciliation as the absolute antithesis of constitutional democracy. But a close win is a win, whether it's with 51 or 50 votes. And given that the vote count in the Senate seems unclear but rather close, it's important for anyone following the debate to realize that the magic number is 50, not 50-plus-one.