The full consequences of the great political hoax of our time — the charge that former President Donald Trump was colluding with Russia — aren’t yet fully apparent. Yet they are surely serious. We have heard from many Democrats and those in media that Trump’s claims that he actually won the 2020 presidential election tend to delegitimize the government and distort the political process. They have a point. It’s a stretch to call the streaming of Trump supporters into the Capitol on Jan. 6 an “insurrection,” but as I wrote at the time, Trump’s words that day “were uttered with...