The_donald members often post in TwoXChromosomes and TropicalWeather?
or
"popping their filter bubbles", or "are generally interested in boundary-pushing ideas", or "are susceptible to the rage-inducing trolls who run fringe communities".
"Affinity for extreme ideas of any kind" maybe a stronger / more common personality trait than "interested in one extreme point in the vector space of ideas".
A broader base of people (about 1/4 to 1/2 of the voting age US public) is aware and supportive of Donald Trump and for a wide variety of reasons, and much more than half at at least aware of Donald Trump. Jordan Peterson has a much smaller following, who are interested in him for similar reasons to each other.