I agree with him that in a debate, all ideas should be discussable. But that's not his argument, his argument is that people can have horrible, destructive and oppressive beliefs and that those need to be tolerated because the people having them are smart. "I feel oppressed because I get flak for having or supporting oppressive and hateful ideas."

My grandpa took me shooting one day. Upon blowing up a gallon jug of water with a rifle, he congratulated me by shouting "You got that Jap!". I know people that exhibit anti-black racist behavior, but have black friends. Many of my Chinese lab mates in Detroit were quite racist against blacks and some against other non-Chinese Asians (Indians, Japanese, etc.). A burka is oppression to me, but I can make friends with men that see it as sacred religious observance. My feelings about sheitels are not too different. I have family members that I love that are homophobic. I am ok if someone thinks that my lack of religion makes me a sinner bound for hell. I am ok if someone thinks that I only have these views only because I am a white male.

We tolerate ideas that we feel are hateful and oppressive every day. Our governments practice them and we rarely protest, or even don't vote.

The point is, ideas are not nearly as dangerous as an the environment that doesn't allow for people to have them, because an environment like that does not diminish the power of these ideas. Instead it creates ideological warfare. At the right moments, I try to persuade those around me to change their minds about ideas that I find are hateful and oppressive. But I do not believe they shouldn't be allowed to express them a priori or conflate that with tolerance. I am tolerating their right to be ignorant. We are all ignorant.

This is true, but there is a really big difference between 'wacky idea' and 'damaging, oppressive idea' that he completely conflates. One is a bit weird and the other is damaging. Is slavery a "wacky idea"?

Slavery was considered a reasonable idea for a long time. I don't know about wacky, but I'm not worried about it catching on in the US even if someone expresses support for it. Is the burka a wacky idea? Is banning it a wacky idea? Is permitting it in a photo ID a wacky idea?

Ideas should be allowed to compete because when they do, they are forced to create a rationale, and that's the worst thing that can happen to a bad idea.