Byron York

After Obamacare passed the House on Nov. 7 -- over the opposition of 39 Democrats and all but one Republican -- Senate Democrats raced to get the job done. Threatening to keep the Senate in session through the holidays, they finally passed the bill -- 60 Democratic votes, not one to spare -- in the early hours of Christmas Eve.

Even as that vote was taken, a little-known Massachusetts Republican named Scott Brown was rising in the polls in the race for Kennedy's seat -- by promising to become the 41st vote against Obamacare. On Jan. 19, Brown's victory shocked the political world. When he was sworn in on Feb. 4, the second period of a Democratic filibuster-proof majority was over. It had lasted 134 days.

But health care had been passed. Later, without a decisive Senate majority, Democrats were forced to use procedural maneuvers to put the final touches on Obamacare. But they were just tweaking what had only been possible with a 60-vote majority.

The last such achievement, Medicare, passed in 1965 with bipartisan support on the foundation of a huge Democratic majority that lasted many years. Obamacare barely scraped by.

Brown's win helped change GOP fortunes. But even with that victory -- and wins by Republicans Chris Christie and Bob McDonnell in the New Jersey and Virginia governors races -- the huge victories that would come for Republicans in November 2010 were beyond the imagination of most observers. Now a new, more balanced Congress will consider what to do with Obamacare. House Republicans will likely vote to repeal the bill, and Democrats, still in control of the Senate and White House, will fight furiously to keep their achievement untouched. As the battle goes on, it will be good to remember the circumstances and lessons of the bill's passage. Given a brief window of opportunity, a determined group of lawmakers can do damage that might take years to undo.


Byron York

Byron York, chief political correspondent for The Washington Examiner