So? Don’t invite him over for tea, but learn how to mock and satirize from him. Rabbi Meir continued to study under Elisha ben Avuya (Aher) even after the latter became a heretic and an informer, because he had something of value to impart, and because Rabbi Meir could winnow out the chaff and take the grain of Aher’s wisdom with caution.
And along those lines, we should use Alinsky tactics on the Left. It’s not as if he invented them. But especially Ridicule, it works!