Every contemporary online community has an orthodoxy, a specific set of beliefs and practices. If you don’t adhere to that orthodoxy, you are rejected. The political left and right are the same in that regard and this principle seems to apply now to every online community that I am aware of, even those that are apolitical.
The election of Donald Trump, and what followed, shocked every online community that I am aware of into a very specific orthodoxy and anyone that does not adhere to that orthodoxy is no longer welcome. Trump’s election was the trumpet blast that destroyed tolerance.
For those who were inclined to be intolerant, the election of Donald Trump made that intolerance socially acceptable. For those who were inclined to be tolerant, the election of Donald Trump drove them from tolerance, to intolerance.
Trump’s election really didn’t signal a change in beliefs, but it very clearly changed the way we all deal with beliefs that differ from our own.