Holding a movement together

The Democratic Party, after having a surprisingly mature start to the primary season, is about to tear itself apart. These frames aren't just angry, they are disrespectful. BernieOrBust pretends to be talking to the DNC, but a huge portion of the Sanders base including volunteers (and likely including Sanders) will be very upset if the Sanders primary plays even a small role in a Republican victory. And "Just Vote Blue" is basically saying "shut up."

What are the real messages, how could each of these movements be reframed to work?