Unlike Senator Paul, neither the president nor the vice president nor the former secretary of state has anything that one might describe as a useful skill. That’s not quite right: They have skills that are useful . . . to themselves. As for skills that are useful to other people — you’d be hard pressed to think of one. If you were a poor family in Guatemala, which would you rather have: the services of a pretty good ophthalmologist, or those of an excellent orator? (Never mind that, unlike Senator Paul, President Obama does not speak Spanish — or, indeed, any foreign language.) Imagine dispatching Hillary Rodham Clinton to Calcutta or Joe Biden to Conakry and then expecting them to do something useful. The idea is preposterous.

Contrast that with professor of orthopedic surgery Tom Price (R., Ga.), obstetrician Mike Burgess (R., Texas), or cardiovascular surgeon Charles W. Boustany (R., La.). Mrs. Clinton may, in making the Hamptons rounds, even pass the childhood home of former physician Howard Dean, whose family split its time between East Hampton and Park Avenue. Even Howlin’ Howard has a useful skill, though his medical license lapsed a decade ago.

Like my friend Jay Nordlinger, I enjoyed Chris Rock’s simple yet subtle twisting of the knife in Jesse Jackson, innocently asking: “So, what exactly do you do?” That really is the relevant question.

What do any of them do?