Now it’s true that most of these Republican reforms, real and hypothetical, would not have insured many people (at least initially) as Obamacare. It’s also true that in the last few years, the G.O.P. has been moving away from even a rhetorical commitment to the goal of perfectly universal coverage. But on both counts I think that the conservative approach is defensible. Given the unsustainability of our existing commitments, the central role that spiraling costs play in making insurance inaccessible, and the difficulties inherent in trying to make Washington responsible for insuring every inhabitant of what will be a nation of 400 million people by century’s end, a reform that expanded insurance substantially but not completely in the short term while putting the health care system as a whole on a sounder footing in the long run (as Bush’s 2007 proposal might have done) could be preferable, on moral as well as practical grounds, to a reform that achieves universality in the near term but ultimately brings everybody on board a sinking ship. (Although “universal but non-comprehensive” is also a plausible way of thinking about what the conservative goal for health care coverage ought to be.)

The big problem facing conservative health care reformers, then, is not the G.O.P.’s unwillingness to embrace universality, and despite what many liberals believe neither is it necessarily libertarian dogma or Norquistian intransigence. It’s a more basic problem of coalition politics: Any substantial health care reform, market-oriented as well as dirigiste, is inevitably disruptive, and (as Reihan Salam points out) the Republican coalition includes more voters who are satisfied with existing arrangements than does the Democratic coalition. As we saw in 2009-2010, to pass a comprehensive health care bill you need not only policy commitments from elected officials but immense internal pressure from the party’s activist groups and rank-and-file. The Republican coalition just isn’t as likely to generate that kind of pressure on its elected officials, and indeed certain segments of that coalition are likely to find reason to resist even the most impeccably free-market reform. Straightforward risk aversion, not ideology, is the crucial factor discouraging Republican politicians from taking the lead on the issue.