I'm tired of settling for the lesser evil.It's more about just needing a Democrat for those appointments, and Hilary has a lot better chance than Sanders in winning the general.
Risking so much for Sanders makes no sense, he won't get any of his policies through congress.
If Sanders can't win, it's going to be business as usual in DC. So it doesn't matter if Hilary wins, she won't be any different from the establishment.