If a bunch of guys are farting in the corner of a debating room and spilling punch on each other while making wisecracks about the hairline of the debators and they get asked to leave the room, the debate isn’t screwed over.
“White supremacists, anti Semites and other racists” – note that.
Who enters a debate with, “Hi, I’m a white supremicist.” “Hi, I’m an anti-Semite”. “Hi, I’m a racist”?
You can enter a debate with, “I believe that society would be improved by encouraging self-similar groups to associate in order to improve mankind as a whole and here are some papers to support my assertion”.
That’s the distinction he’s talking about.