I don't think anti-Trump conservatives are particularly unwelcome in mainstream American conservatism though. Take someone like the Orthodox Christian journalist Rod Dreher, who says very negative things about Trump ("Donald Trump is flat-out lying to manipulate the political process", [0]), but who has also written a book (Live Not By Lies) claiming that American progressivism is evolving into Soviet-style totalitarianism. Getting invited on to Tucker Carlson's show is a pretty clear sign of being welcome by mainstream American conservatism, and Carlson has invited Dreher (in September last year) on to promote his book, and I'm sure the Fox News audience loved it. Carlson just avoided asking Dreher about his opinions on Trump, he knows what his audience likes and he didn't get where he is by upsetting them.
[0] https://www.theamericanconservative.com/dreher/donald-trump-...
Right, there's no market for dissent, only for the tribal-conformist views.
Actually I do wonder whether centre-left media outlets have the same freedom that Carlson has, to platform dissenters to talk about matters unrelated to their dissent.
Unless by “...against cancel culture” you mean “...who deny thr existence of ‘cancel culture’ as a significant new or especially liberal/left phenomenon”, but then, those arent dissenters at all.