Sadly, there have been Nazi and white supremacist rallies all over the country, often and every year for quite some time. It's really sad, but that's the reality.
But I think is more notable recently, and more disturbing, is that they're getting more press and less pushback from the media rather than being ostracized and ignored as they have been in the past.
So... don't engage with them then. You don't have to reply. They don't have to either. You're both fanning the flames of arguments you both claim you don't want to have.
This is what surprises me. His show, even in the early days, was never worth sticking around for. Rogan tried to be an actor long ago, had a whiff of success and then it fizzled out because he sucks. Then he tried to be a comedian, and that also had a whiff of success but fizzled out because he sucks. So he tried being a reality show host, got some traction, then failed out of that as well. His podcast is just his last attempt to be relevant and famous. And because he failed at the others he's desperate enough for attention to do this kind of content with bigots and science deniers. He's opportunistic trash.