It was a telling moment in the GOP’s continual descent into a post-truth party in the Donald Trump era. Even though multiple fact-checkers debunked a claim that the Taliban hanged a man from a U.S. helicopter left behind in Afghanistan, many Republicans who promoted the claim refused to back off it. And Donald Trump Jr. ultimately went so far as to replace the banner on his Twitter page with a mock Biden campaign logo featuring an illustration of the supposed helicopter hanging.