Before the last election, the actor Michael J. Fox, who suffers from Parkinson’s and has become an advocate for stem cell research that might lead to a cure, made an ad in support of Claire McCaskill, the Democratic candidate for Senator in Missouri. It was an effective ad, in part because Mr. Fox’s affliction was obvious.

And Rush Limbaugh — displaying the same style he exhibited in his recent claim that members of the military who oppose the Iraq war are “phony soldiers” and his later comparison of a wounded vet who criticized him for that remark to a suicide bomber — immediately accused Mr. Fox of faking it. “In this commercial, he is exaggerating the effects of the disease. He is moving all around and shaking. And it’s purely an act.” Heh-heh-heh.

Of course, minimizing and mocking the suffering of others is a natural strategy for political figures who advocate lower taxes on the rich and less help for the poor and unlucky. But I believe that the lack of empathy shown by Mr. Limbaugh, Mr. Kristol, and, yes, Mr. Bush is genuine, not feigned.

Mark Crispin Miller, the author of “The Bush Dyslexicon,” once made a striking observation: all of the famous Bush malapropisms — “I know how hard it is for you to put food on your family,” and so on — have involved occasions when Mr. Bush was trying to sound caring and compassionate.

By contrast, Mr. Bush is articulate and even grammatical when he talks about punishing people; that’s when he’s speaking from the heart. The only animation Mr. Bush showed during the flooding of New Orleans was when he declared “zero tolerance of people breaking the law,” even those breaking into abandoned stores in search of the food and water they weren’t getting from his administration.

What’s happening, presumably, is that modern movement conservatism attracts a certain personality type. If you identify with the downtrodden, even a little, you don’t belong. If you think ridicule is an appropriate response to other peoples’ woes, you fit right in.