I don't know why Bernie Sanders was talking about Hitler winning an election, but he was wrong, and his followers were retweeting his misinformation. I suspect as a socialist he was trying to avoid any connection with the Nazis (National Socialism) and wanted to pin that label on conservatives.
Nazis were all for government control; they were statists. They killed and imprisoned their own citizens, as did the Communists in the USSR. No Republican administration or Tea Party or libertarian group in the U.S. have done that, but Democrats have. Hillary Clinton has made up new lies about women, based on nothing but her desire to crawl out from under her email server which has collapsed on her. Why can't these candidates tell the truth?