After the debate debacle in Atlanta on June 27, the well-known hand-wringing tendencies of the Democratic Party are in very plain view. That’s particularly true in the left-of-center pundit class, where full-blown panic has erupted over the terrible sight and sound of Joe Biden struggling to debate Donald Trump. We still don’t know the extent to which American voters share the horrified perceptions of Democratic elites; those not accustomed to Trump’s own routine...