The DS chose their candidate long ago.
An endorsement from Barry would ensure that candidate wins the primary so why not endorse? The DS is already bribing, black mailing, exposing Democrat candidates to move the chosen into place.
Could it be that the DS believes Barry will be the first arrested?
If ALL of his crimes are exposed when arrested, it would ensure the candidate that he endorsed is sunk forever, and since they believe they still have a chance, they wont let Barry endorse.