Byron York

Obamacare is filled with vulnerable provisions. In addition to the 1099, there's the individual mandate (which is also being challenged in court), cuts to Medicare and the long-term-care measure called the Community Living Assistance Services and Supports Act, better known as the CLASS Act. During the Senate's Obamacare debate in December 2009, some Democrats voiced reservations about each of those provisions.

"Just look at the ones who made noise during the original debate," says a well-connected GOP Senate source. "Claire McCaskill, Ben Nelson, Kent Conrad -- Conrad called the CLASS Act a Ponzi scheme, but he voted for the whole bill that included it. How would he vote on a separate bill to repeal it?"

We'll probably find out. In the next year and a half, Senate Democrats, including some who are facing tough re-election fights in 2012, could have a chance to vote again on the most troublesome parts of Obamacare. With 47 Republican senators, the GOP would need just four Democrats to reach majority support for repealing significant chunks of the healthcare law.

If that happens, Senate Democrats, who at this moment are railing against Republican filibusters, would have to resort to -- you guessed it -- a filibuster to stop repeal of any part of Obamacare. Even if they do, Republicans believe they might muster 60 votes to win the day. And if key parts of Obamacare fall, it's not clear whether the whole structure can remain standing.

As those fights go on, House Republicans, with some Democratic help, will pass new measures to address the healthcare problem piece by piece. Some will be attractive to Senate Democrats facing re-election. "A lot of them come from states that are sympathetic to the message we heard last Nov. 2," says Dreier. "So in light of that, we're not going to give up on this."

Byron York

Byron York, chief political correspondent for The Washington Examiner