The Democrats could take an enormous risk and run the most popular politician and the country, but they definitely won't do that. Instead they could run a former prosecutor or a guy who's greatest political moment thus far was losing statewide office.
Lots of Democrats really really hate Bernie. Probably more than any Republicans
It's not Dems and Pubs, but upper class that fear him. He's for the working class, and therefore, a threat to the way big gov. collects tax. That's why the majority of his supporters were middle class. He was very poplar with young people, due to his speeches about getting big gov. off the working man's back.
I know he sounds like a commie, but is he?