Self defeating move. The Sanseito kid approached the anti-racist crowd to make a provocation, but the white guy debating him just comes off as an arrogant fat fuck. Liberals frequently make the same mistake trying to debate livestreaming provocateurs because they don't realize the content of the argument is secondary to the optics and end up taking the bait.
he right way to handle this would have been to show respect for the kid and respond with some vague platitudes like その意見がすごい重し鳥ですけど、もし信じられなりかもしれん.... while just hearing him out politely. ('those are some interesting opinions, but I don't know if they're really believable...'
It takes two to make an argument, so being baited into one is stupid. An anti- demo like this during election season also strikes me as a bit stupid. It's one thing to put up signs expressing your opposition to something but trying to outshout people during a jp election campaign is like asking the rain to fall upward. He and the other dmeonstrators would be better off doing positive support for CPJ or whoever.