The most important factual evidence posted on this thread so far, is the fact that the Secret Service wanted Bush to stay there because they couldn't guarantee his safety at that moment.
That pretty much shoots down any crap anyone here is trying to spew that Bush didn't do enough after Card told him.
I think making sure the President doesn't get assasinated during while being attacked is high on the priority list.
Especially since there's very little the President could have done anyway, as there were no armed aircraft close enough to Washington to make a difference.