You know this guy is an anti-Muslim, white supremacist, right?
Are you out to examine stuff or out to "win points"?
I'm out to examine stuff, I don't care about "winning points" or debating.
The superficial approach of this-guy-is-a-such-and-such-and-therefore-don't-listen-to-anything-they-said makes sense as a debate tactic, if you want to score points. Someone else used the same debate tactic in relation to Bart Ehrman ("Bart Ehrman is an agnostic, don't listen to his stuff about textual criticism").
Someone else used the same debate tactic when I quoted Mao ("Mao killed people, therefore his quote is not valid").
If you want to get into ad hominem fallacy, you can get into ad hominem. A lot of people only care about appearance and "scoring points" as opposed to truth logic.
The guy is a white nationalist? I really don't care. Trump is a white nationalist. I'm not a white nationalist but I agree with the anti-abortion stuff he was for.
If you and the others who use that debating tactic think you either have to agree with everything a person says or agree with nothing they say- you can follow that reasoning. I can agree with people on one thing and disagree on other things. I am fine with hearing different points of view.
Some people care about logic. Some people don't care about logic. They don't care things like "ad hominem fallacy". If you don't care about logic, you're free to make superficial statements, not care about logic and ignore logic.