Based on this famous picture: 
Yeah Trump has always been a vocal teetotaller because of Fred Trump jr.
When his alcoholism prevented him from continuing to function as a pilot, Trump returned to work for his father's business. He eventually moved into the unfurnished attic of his parents' house and again did maintenance on Trump properties.[20] On September 26, 1981,[21] at the age of 42, he died from a heart attack caused by his alcohol use.[22][23][b]
He's got a chip on his shoulder about alcohol specifically being a pathetic vice for weak losers.
(Uh, to be clear I am describing Trump's thought process there. I, myself, am someone who abuses the so-called pathetic vice for weak losers. Not trying to hit anyone with strays on this.)