Fred Barnes has the best analysis of the legislative prospects for Obamacare.

There's one tricky part for Republicans in the health care fight. They don't want the bill to be improved--that is, made a bit less sweeping and draconian. The bill can't be improved sufficiently to satisfy Republicans, but it might become more palatable to worried Democrats. Republicans can probably count on liberal Democrats to prevent this by rejecting moderate amendments (which would face the 60-vote hurdle).

The shrewdness of McConnell's emphasis on the vote to proceed will become clear when the final cloture vote--which would end debate on the bill--is taken. Democratic senators with qualms about Obamacare are likely to have voted for the motion to proceed, explaining they'll seek changes in the bill. In all likelihood, those changes won't be approved. Obamacare will have emerged from weeks of debate roughly the same. Will moderate Democrats then vote for cloture on the motion to end debate?

This is the key vote. Reid will likely need to hold all the Democrats. Here Obama's role is crucial. It may be up to him alone to keep Democrats from defecting. One or two votes could decide the outcome. If Obama fails, his health care initiative may die.