Gramm was responding in the approved manner. Politicians, most of whom are the sort of people who take themselves too seriously, take very seriously the dangers inherent in appearing to take themselves too seriously. Politicians are supposed to be nearly insult proof, in the way that people associated with the Mob are libel proof. Not so animals. I've pointed out, though, that any commentator who said Quayle had a stare like a deer caught in headlights was bound to get more letters from deer lovers than from supporters of the Vice President.
Politicians realize that confronting an insult head-on starts voters thinking.