This exchange was the emotional high-point of the Las Vegas debate:

Some observers thought Mitt Romney lost his cool. Others thought he showed rarely seen fire in shutting down Texas Gov. Rick Perry. (In these contests the guy who is forced to shut up usually comes across as the weaker of the combatants.) But I want to focus on two aspects of the encounter.

First, it was low and false for Perry to claim that illegal immigrants are responsible for his exorbitantly high rate of uninsured Texans. As I have reported before, even if you assumed every illegal immigrant to be without health insurance and even if you took out all illegal immigrants from the pool of uninsureds, Texas would still be the third worst state in terms of health care. For someone who wants to court the Hispanic vote, he has a strange way of going about it — scapegoating illegal immigrants. In point of fact, Texas wouldn’t stand out like a sore thumb if its Medicaid qualifications were akin to other states and/or Perry earlier had instituted effective policies to encourage Texans to sign up for Medicaid and the CHIPS program.

Second, Perry is setting himself up for trouble by focusing on a topic on which he is hurting badly with his key voters. If there are voters for whom immigration is the key issue, I suspect they aren’t voting for Romney anyway; they’ve probably drifted between Perry, Rep. Michele Bachmann (R-Minn.), Herman Cain and the others. By bringing up the topic, Perry only reminds his base (or what used to be his base) of the issue that drives them nuts.

Put it this way, Cain, Bachmann, Santorum and the rest would be thrilled for Perry to talk about immigration all day long. Perry, probably out of personal pique, doesn’t seem to understand that his real problem is not Romney but the other Tea Party-friendly candidates who have eaten his lunch and taken his voters.