I agree with the people that differetiate between drinking, and drunk. I frequently will have a glass of wine or a beer at home. That is not enough to impair me and I wouldn't consider myself drunk. Very rarely I might have 2-3 drinks in a night, and would consider myself to be slightly impaired or "drunk". I don't see a problem with handling a firearm after drinking if not impaired, but I agree that handling a firearm while impaired is a horrible idea in most cases.
Note I said in *most cases*. I *generally* will not handle a firearm while impaired. In a life or death situation I would not let a buzz from a few beers keep me from defending myself and my family though. I honestly don't know what the legal ramifications would be if I had to defend myself while under the influence, but given the laws about self defense in my state don't mention it, I don't see it being a problem.