Do you remember a few decades ago when one of the main complaints about politics was that Democrats and Republicans were not so different? Not anymore. The news industry has found that polarization is a strong business model. The first group of pundits claim many times a day that Republicans are right about nearly everything and Democrats are stupid and evil, while the second group do the reverse. Voters tend to consume news that agrees with their opinions, thus reinforcing them. In this environment, you can’t reasonably expect the folks who voted for the losing candidate to warm up easily to the winner. In the past the differences between victor and vanquished in the political arena were mostly questions of policy. To partisans today, Hillary Clinton and Mr. Trump are a lying, cheating murderer and a crazy, impulsive, lying, racist, homophobic, sexist narcissist. That’s a big gap.
And it’s not as if Mr. Trump’s opponents are eager to close it. Michael Jordan missed about half of the shots he attempted. That isn’t because he lacked skill, but because the opposing players were highly capable at defending. Likewise, the political and media professionals who oppose the president are playing unusually strong defense, and that works against his job-approval ratings.
Example: Anti-Trumpers take it as a given that this president is a racist. As evidence, they point to a series of news stories and quotes that seem to support that position. Your common sense tells you that even if some of the claims are exaggerated or taken out of context, there are so many of them that they can’t all be wrong.
But as any cognitive scientist will tell you, they can all be wrong, and that wouldn’t be unusual. Confirmation bias looks exactly like a mountain of evidence. If that sounds crazy, consider how much solid evidence the press gave us in 2016 that Mr. Trump could never get elected...