What is the common thread that links almost all of these crazies? I mean, even more than religion.
Conservatism. Almost all of them vote for, or are elected representatives of, conservative parties.
And conservatism encourages divisiveness and bigotries like this. To be suspicious of and actively hate others, to find “evil” where none exist. To believe in falsehoods even when they have been demonstrably debunked.
Conservatism of all stripes is fundamentally evil. Conservatism is what will destroy civilization, and eventually, humanity.
Welcome to climate change. This is just the tip of the iceberg: things are just going to continue getting worse and worse each and every year.