The amount I drink doesn't seem to have much of an impact upon my weight. I was much lighter when I used to drink all the time but my body fat % was probably around the same as it is now.
I'm sure in most cases people that drink a lot get fat because they overeat when drunk, and most likely whilst sober too. We get a bunch of news articles every so often about the calories in alcoholic drinks but everyone seems to ignore the really basic facts that calories are a measure of energy and that the human body can't do shit with certain sources of energy (e.g. coal, wood, ethanol) so as 'calorific' as something like vodka is, it's not going to make you fat.