Would President Obama sign a death warrant on his own signature legislation? That’s almost impossible to imagine, but it’s entirely reasonable that he may not have a choice in the matter. Consider: Despite the White House’s protestations, 62.4 percent of the House voted for Michigan GOP Rep. Fred Upton’s legislation (261-157), just shy of the two-thirds necessary to override a veto. And consider the House Democrats who voted against Upton’s bill but nonetheless released harsh statements criticizing Obamacare. Maryland Rep. John Delaney, in a statement, wrote: “The problem we have currently is that the Affordable Care Act is not working.” Added Arizona Rep. Ann Kirkpatrick: “The stunning ineptitude of the ACA marketplace rollout is more than a public relations disaster. It is a disaster for the working families in my Arizona district who badly need quality, affordable health care.” Add them into the mix — the dozens more members who were poised to split with the president until his face-saving press conference — and you’ve got all but the hardy Obama loyalists who could end up bolting if the political environment doesn’t improve.

Democrats are in better shape on the Senate side, but not by as much as conventional wisdom suggests. Senate Majority Leader Harry Reid will do everything in his influence to protect the president — and block embarrassing legislation from being voted on — but not if it means he’ll be losing his majority gavel next year. There are 21 Democratic held-seats up in 2014, with 17 Democratic senators running for re-election. Of those 17, 10 are running in states where Obama won less than 55 percent of the vote, approximately the baseline of where House Democrats began splitting with the president on the Upton vote. Excluding Reid, an additional 15 Democrats aren’t up in 2014, but represent battleground (< 55% Obama) states where support of the law could become a long-term burden. And then there's California Sen. Dianne Feinstein, who has emerged as a surprising blue-state critic of the law, retiring Montana Sen. Max Baucus, who famously predicted the implementation was shaping up to be a "train wreck," and retiring moderate South Dakota Sen. Tim Johnson. To overcome a veto, Republicans would need 22 of those 28 winnable votes. Right now, they wouldn't come close. But Reid and the White House may end up relying on swing-state Democrats like Claire McCaskill and Bob Casey to protect the law. If the political mood doesn't improve in short order, will they want to be in that position? And if Republicans retake the Senate in 2015, the political momentum for repeal would only grow.