The Democratic convention in Charlotte, N.C., proved the old adage that everyone makes mistakes.

There were some big but understandable mistakes, such as the last-minute move of Obama’s acceptance speech indoors, which sparked talk that the president couldn’t fill the stadium. There were also a few embarrassing and less understandable miscues. For example, high-ranking party officials (notably including state party chairmen from California and South Carolina) seemed irresistibly drawn to comparing their opponents with Adolf Hitler’s murderous Nazi Party.