David Cay Johnston: You agree with Bernie Sanders (but you might not know it)

The zeal of Bernie Sanders supporters is a mystery to many people, especially those who cringe at the word "socialist."

How, can a geriatric Brooklyn-born Jew who speaks in long, complex sentences, his hands providing the punctuation, draw bigger crowds than Donald Trump, despite claiming a tiny fraction of the mogul's TV news coverage? How could he battle Hillary Clinton to a virtual tie in Iowa, with a good chance of beating her Tuesday in New Hampshire? How could he be closing the gap with her in national polls?