Mitt Romney's Republican opponents charge that under his health care reform, there are long wait times to see doctors.

They also say primary care physicians are less likely to see new patients than they were before.

And they're right — according to Jonathan Cohn, a left-of-center supporter of President Obama's health care reform.

There just doesn't seem to be any evidence that Romneycare caused those problems. Cohn explains why at the link.

But I suspect that Cohn's approach — rigorously scrutinizing the relevant data — is not exactly going to dominate the discussion in the 2012 Republican presidential primaries.

A commenter on Cohn's post adds that even if Romney's state health insurance law does lead to negative consequences, we shouldn't assume that a national version of Romneycare (which is more or less what Obamacare is) will lead to similar consequences:

I know a (poor) woman who had moved from MA to Florida a few years ago. When universal health care was introduced in MA - and she subsequently got pregnant - she moved back. Though I haven't seen any studies it seems likely that such "market forces" are drawing a number of indigent people in which would tend to increase the load on the system. . . .

[This] problem is solved immediately by a national plan.

The theory of federalism says that states act as "laboratories of democracy," allowing us to see the consequences of policies on a relatively small scale before deciding whether to enact them nationwide. But individual states are so different from the entire United States that the results of a state-level policy experiment might be meaningless or even worse.