I have watched several of his Youtube videos. He does not express radical opinions or make strong arguments. Mostly he makes general and oblique comments about current political events and what he considers the Alt Right movement. He occasionally says he prefers ppl of similar ethnicity to himself, but that is true about most of the world.
What he does do is trigger hatred of white ppl. Spencer does not advocate white supremacy, but the protesters against must give many observers a better argument for white supremacy than anything Spencer would say anyway. The protesters seem like lunatics, fascists, criminals, and undesirables. Spencer seems calm and rational by comparison.
A Martian might conclude that folks like Spencer should be running the country, while the protesters should not be allowed to vote.
I think that the protesters would be much better off ignoring Spencer. Nobody would have heard of him, if it were not for these protests.
Update: Gateway Pundit claims Spencer is a Deep State plant.
It is clear to anyone with in IQ above room temperature, that, if you are on the right, and you are going to an event organized by Richard Spencer, Jason Kessler, Mike Enoch, or Eli Mosley, you are, what Spencer’s hero Lenin called, a “useful idiot”. You are going to be photographed, documented, and you are going to have an FBI file labeled “Domestic Terrorist” on it for the rest of your life.