Calling people you dislike “stupid” and “low intelligence” is indicative of bigoted attitudes.[0] While I'm in favour of reclaiming some meaning from the word “stupid”,[1] what you're doing here is not that. If you care about this sort of thing (which you seem to), you might want to reconsider how you go about it.
> > Using circular logic
It is best for your criticisms of things to be founded in truth, where possible. The first and last resort is the truth. It's a good habit to get into. There were plenty of other things you could have said, including:
> No, it's actually quite relevant.
You needn't worry about the truth justifying bigotry, in case that's the issue: while it's theoretically possible for a given piece of bigotry to have a basis in fact, reality seems to have some rather strong opinions on the matter! :-) If bigoted rhetoric had a habit of being correct, I think I would've found out by now. And if it were true, you would expect to see certain kinds of bigotry popping up in multiple places independently; rather than having traceable provenance, either as adaptions of prior bigotry, or as traced back to a historical figure with a strong and documented motivation for having people believe it.
That's not to say you need to put much effort into responding. But if you feel like putting that little effort in, it's best not to respond at all.[2]
[0]: https://thebodyisnotanapology.com/magazine/stupid-is-an-able...
[1]: https://web.archive.org/web/20110824041258/http://www.stupid... (see especially page 24)
[2]: https://en.wikipedia.org/wiki/Wikipedia:Deny_recognition