My litmus test is climate change denial - for some reason truly insufferable people consistently have this one thing in common. Sure enough among the quotes is

My litmus test is climate change denial - for some reason truly insufferable people consistently have this one thing in common. Sure enough among the quotes is an excerpt form a 1974 Time magazine article about global cooling, which is a dog whistle for "the science is not settled". My sister had to suffer through a few courses with a professor who gave such enlightened opinions as "men should be paid more, because they eat more than women". Fortunately the students managed to make him lose his position as a lecturer on the grounds that he ranted instead of actually giving the lecture.