That excuse pisses me off so much. One of my high school teachers had a sticker in his classroom that read: "Impairment Begins at the First Drink." (I think that he lost a family member to a drunk driver), and that always stuck with me. I'm a chubby guy myself, and I've played around with those calculators that attempt to estimate how much I'd have to drink to get over the legal limit, and let me tell you, I notice a decrease in my faculties LONG before I hit .08.His fans stick up for him by saying because he's fat he can drink more thus he is ok to drive home.
I recognize that everyone's body is different and responds to alcohol differently. I guess Nate could be enough of a functioning alcoholic that the first few beverages don't affect him much... but I still think he's playing with fire every time he gets behind the wheel after drinking.