Donald Trump views the mainstream press with contempt, and the mainstream press returns the favor. Or is it the other way around? Just as the president has trouble distinguishing between negative press coverage and “fake news,” the journalists who cover him tend to treat every inaccurate, unfounded, or even debatable statement he makes as a lie. And that mistake, suggests Jacob Sullum, clouds the judgment and damages the credibility of reporters and commentators who aspire to skepticism but too often settle for reflexive disbelief.