A prohibitionist is the sort of man one wouldn’t care to drink with — even if he drank.

H. L. Mencken (1880-1956) American writer and journalist [Henry Lewis Mencken]

A Little Book in C Major, ch. 3, § 10 (1916)
    (Source)

Variant:

PROHIBITIONIST. The sort of man one wouldn't care to drink with, even if he drank.
A Book of Burlesques, "The Jazz Webster" (1924)