Hilter killed a lot more than 6 million. Let's not discount all the folks who died in the war that he perpetuated. Just ask the Russians.
I don't think Obama will invade countries and encourage his troops to rape and murder entire villages so that bored "real Americans" can go farm their land. I think he'll screw up some, in general be a competent leader, and at least tell the rest of the world that we're not a country of white supremacist, Apocalypse-baiting Christian fundamentalists. That's why I'll vote for him, one of several reasons.