That's a good point. He's anti-establishment which currently makes him very popular with the alt-right since they can rally around his conspiracy theories about democrats/Israel/whatever else they don't like. So not self-described alt-right but someone who has been lumped into that pile due to some of his views over the last few years.

Unrelated but I have a sneaking suspicion the alt-right will break with him anyway as soon as he starts focusing more and more on conspiracies about Trump.