Here at the American Political Science Associations convention, Lawrence Jacobs, a scholar of public opinion with a particular specialty in health care, just gave an interesting presentation on the three possible paths he saw for health-care reform going forward:

1) Redemption: Think of this as “the Medicare scenario.” As Jacobs noted, there was a fierce fight over Medicare’s passage. There was a real battle over implementation, in which the American Medical Association threatened a doctor's strike and Lyndon Johnson seriously considered mobilizing the army over concerns that the South wouldn't abide by a law that extended health insurance to African Americans. But within a few years, the furor calmed and the law "slid into acceptance." Jacobs considers this the least likely scenario for the Affordable Care Act.

2) Repeal: The historical model here would be the repeal of the Catastrophic Care Act. As Jacobs noted, you don't need to reach to imagine how this will go: Republicans won one election in part on a promise to repeal the Affordable Care Act and, in 2012, they might win another. He considers this the second-likeliest scenario for the law.

3) Resistance: This is the Social Security scenario. As Jacobs told it, Social Security went through decades of fights, spats and setbacks. The financing was initially delayed, and there was talk of scaling back the program. Over the years, there were repeated showdowns over who the program would cover and how generous — or sparse — the benefits would be. It took a long time for the program to firm into the unquestioned edifice of the social welfare state that it now is. Jacobs seemed to see this sort of a process — one marked by continuous skirmishes, setbacks and pushes forward — as the likeliest future for the law.

I'd add one more: Reform. If Republicans don't take back the presidency next year or they do take it back but they find themselves unable to repeal the law (perhaps because Democrats emerge with either the Senate or the House), I think it as likely as not that, at some point down the road, the two parties will reach some sort of agreement in which Republicans semi-officially admit the law's permanence in return for certain concessions. 

Those concessions could be a greater role for state experimentation, perhaps through some supercharged version of Wyden-Brown, or a more specific role for high-deductible plans (though they are already more prevalent in the law than most people realize), or a more significant change to the tax system, perhaps though a McCain-esque conversion of the deduction for employer-provided insurance into some sort of standard credit that all individuals can use to purchase insurance, or a change to the law's enforcement mechanisms, perhaps through the repeal and replacement of the individual mandate. But if repeal fails and Republicans realize that the law will be around for awhile, I expect that they're going to begin looking for some package of reforms that they could use to accommodate themselves to the new reality while saving face.