He bashes Bush because Kerry is not giving Leno any ammo.
Relax.
I've always thought Leno was an equal opportunity basher but I stopped watching because it's become just a free promo for the latest Hollywood personality or flick. Most of these "stars" can't string an intelligent sentence together anyway and none seem to have any biographical material that's the least bit interesting.
If Leno seems to go after Bush more just take comfort in the fact that most viewers are teenagers or welfare cases who won't vote anyway.