The Washington Post has an article looking at President Bush’s National Guard service, or lack thereof.
There’s no definitive evidence either way. On one hand you have an officer who claims that Bush didn’t report during part of his enlistment, together with an absence of any hard evidence that Bush showed up. On the other hand you have Bush claiming he was there, and some friends saying Bush left for duty.
Whatever the case, it’s obvious that Bush didn’t take his Guard service very seriously. If he did, we’d have proof to settle this.