The hack gap explains why Clinton’s email server received more television news coverage than all policy issues combined in the 2016 election. It explains why Republicans can hope to get away with dishonest spin about preexisting conditions. It’s why Democrats are terrified that Elizabeth Warren’s past statements about Native American heritage could be general election poison in 2020, and it’s why an internecine debate about civility has been roiling progressive circles for nearly two years even while the president of the United States openly praises assaulting journalists.