I know they are for real, because I know some of them. They won’t ever admit it to another Democrat, and often not to each other, but some have told me because they know I support Trump. These are well-educated life-long Democrats who have never ever been tempted to vote for any Republican, with the exception of Giuliani. What seems to motivate them, mostly, or at least the ones I know, is an inability to vote for Hillary and keep their self-respect. This means that if Bernie is the nominee, they will revert to voting democratic.
I wouldn’t be surprised if there is some crossover with Sanders and Trump. Both preach economic populist (bring the jobs back home) rhetoric.
i also know many of them. I guess to the media - they aren’t real just as the numbers at his rallies aren’t./s