Barney Frank regarding Bernie supporters:

I am disappointed by the voters who say, “OK I’m just going to show you how angry I am!” And I’m particularly unimpressed with people who sat out the Congressional elections of 2010 and 2014 and then are angry at Democrats because we haven’t been able to produce public policies they like. They contributed to the public policy problems and now they are blaming other people for their own failure to vote, and then it’s like, “Oh look at this terrible system,” but it was their voting behavior that brought it about.

It is a good interview