Something is rotten in the state of American political life. The U.S. (among other nations) is increasingly characterized by highly polarized, informationally insulated ideological communities occupying their own factual universes.
Within the conservative political blogosphere, global warming is either a hoax or so uncertain as to be unworthy of response. Within other geographic or online communities, vaccines, fluoridated water and genetically modified foods are known to be dangerous. Right-wing media outlets paint a detailed picture of how Donald Trump is the victim of a fabricated conspiracy.
None of that is correct, though. The reality of human-caused global warming is settled science. The alleged link between vaccines and autism has been debunked as conclusively as anything in the history of epidemiology. It’s easy to find authoritative refutations of Donald Trump’s self-exculpatory claims regarding Ukraine and many other issues.