At a certain level, this is all terribly silly. Obama's policy, like Romney's policy, is a moderate solution to a long-standing national problem. Their plans are the sort of thing that can enjoy bipartisan support -- and would had the GOP not gotten so hysterical and extreme in recent years.
But that is, of course, the point. Romney did one big thing during one term, and now his own party doesn't want to hear about it. On the contrary, they're demanding an apology before they hear anything else.
The irony for Romney is that he's flip-flopped on practically every issue I can think of, but the one position he's inclined to stick to is the one the GOP base finds wholly unacceptable.
It's worth noting, though, that it's not just Romney. Jon Chait added, "I'd also be curious to hear from some conservatives about how they see this. In 2008, nearly all of them were fine with Romney's health care plan. (National Review endorsed Romney for president.) Now, to a man, nearly all of them believe the imposition of a regulate/subsidize/mandate scheme represents one of the worst catastrophes in American history. How do they account for their dramatic change of mind? Were conservatives all simply wrong and ignorant in 2008, and now they've opened their eyes?"
UPDATE 2:21pm Pacific:
Finally put up the Jonathan Chait piece mentioned by Mr. Benen:
Politico has a good piece today on a subject I've been banging on for a while -- the mortal blowinflicted upon Mitt Romney's presidential hopes by the health care debate. In 2008, a system consisting of a regulated individual markets, an individual mandate, and subsidies for low-income workers was considered a perfectly sensible thing for a conservative Republican to have supported. Romney boasted about it on the campaign trail and took essentially no flack for it. Now, such a system is The Death Of Freedom.
The further problem is that the 2008 version of Romney was itself a radical remaking of his prior political identity. Romney took a great deal of abuse for his shift, but ultimately conservatives swallowed it, and he emerged from 2008 in a strong position. His post-election speech to the CPAC positioned him as a front-runner. But now health care has killed it. The Politico story quotes some conservatives demanding Romney apologize. He can't do that, of course, without raising all the flip-flopper questions that haunted him four years before.