What you said was, "Where do I mention Bush?" People can decide for themselves whether that sounds like a denial. In any case, thank you for acknowledging the fact that he is the person you were talking about. It was quite clear it wasn't a random college student you were referring to - which is fine, but I really didn't get the, "Wha...? Who...? Did I actually say the name 'Bush'?" thing.
But to try to use this particular example to prove that I go around engaging in personal attacks is unfair, IMHO.
Did I say something about a personal attack? (I may have, though I have no memory of that.) What I said was that it was disingenuous to deny you were talking about the POTUS. That's not an accusation of a personal attack. It's an accusation that you were being insincere in your response about who you were talking about.
If I wanted to use that issue as a personal attack on Bush, at the very least I would have mentioned his name. But certainly you'll never find me showing up on a pro-Bush thread (like Day in The Life of...or a thread praising Bush for a speech he gives, etc.)and bringing that kind of stuff up. But the Keyes bashers here do that kind of thing all the time.