Webb is a jerk, and Dubya needs to work on his comeback lines.

Sadly, it's apparent that more than one word is necessary here: Bush is the one being a jerk.

As for Webb, the evidence rather points the other way.

This is just "he said/she said" at most. Actually, it's hearsay, since the conversation is being reported by an anonymous third party. But even if we assume something like the reported conversation took place, it's far from clear that either Webb or Bush was being a jerk. A lot depends on the intonation and other non-verbal communication that took place.

It's also possible, of course, that there was a misunderstanding. Perhaps Webb was simply meaning to mention that he and his family look forward to having their son home, but Bush interpreted this as a "bring the troops home now" political slogan in reply to his kindly inquiry about Webb's son.