The Dems are desperate to get control over the judicial appointments, the most obvious being the next SC appointment. If Bernie wins the nomination, an awful lot of Dems are going to stay home; this will impact Senate races across the country.
They want to put the most moderate voice as possible at the top of the ticket for no other reason than to try to win the Senate back, even if they still lose the White House. With a Crazy at the top of the ticket, they've lost the WH and the Senate as well.
The Democratic Convention could be a rerun of 1968.
Time to stock up on popcorn—before there are shortages!