Having navigated the thickets of thickly drawn party lines on taxes, President Obama now must overcome a potent force inside his own Democratic Party: pride.
But the Democratic anger that erupted on Capitol Hill last week will continue to play itself out. At its heart, it stems from long-held skepticism about the White House's commitment to core party values -- and shorter-term rage that the president chose to capitulate on a defining distinction between the two parties.
The extraordinary display of disappointment voiced by House Speaker Nancy Pelosi and her caucus appears unlikely to substantially change the tax bill.
The president has too much riding on the outcome to let it collapse, and a Senate vote early this week will likely provide momentum toward final passage in the House, Democrats' objections notwithstanding.
Democrats in the House and the Senate will instead have to settle for a few token victories, including some extended tax credits for renewable energy initiatives and modest changes in the estate tax provisions.
The fight has broader implications for a party that's still reeling from last month's electoral "shellacking." Many Democrats feel the president's actions over the past two weeks added injury to the insults delivered by voters.
The president has effectively declared his independence from the Democratic base. His actions last week, starting with the tax deal and extending through news conferences and public appearances, framed Obama as hovering above partisan politics -- a useful position for 2012, if not for the balance of 2010.
That's driving tensions during the lame-duck Congress. House Democrats remain in charge officially, but they've seen their power begin to diminish already, with the president among those who've hastened a de facto transition.
All of that points toward a way for Democrats to acknowledge the political realities and not hold up a tax deal that would leave them shouldering blame for having taxes go up on all Americans.
Yet for all involved to be able to work cooperatively in the new Congress -- where the president will of course need Democratic votes -- the White House will need to find a way for House Democrats to save some face.
In the meantime, the rest of the lame-duck session is being held up by the tussle over taxes. The most conspicuous potential casualty is the effort to repeal the military's "don't ask, don't tell" policy banning gays and lesbians from serving openly.
This is a case where one side almost certainly has the votes, but is dangerously close to not having the time. Debate on this issue -- which got wrapped up as part of the broader Defense Authorization Bill this year -- was put off for months given the political cross-currents.
Now, Senate leaders are scrambling to find enough time to have the debate, while most Republicans are intent to run out the clock.
The stakes extend well beyond the current legislative session: Congress is highly unlikely to take up a repeal in 2011 or 2012, since House Republican leaders who control the floor schedule remain overwhelmingly opposed to getting rid of the policy.