State Assemblyman Bronson doesn't represent the district the mayor lives in, so he's no threat to her. She doesn't want his job, anyway. That would necessitate taking a pay cut by nearly 50%. So the mayor could afford to be gracious and endorse Harry, which is completely out of character for her.
On the other hand, Bronson never needed the support of Lovely Warren or David Gantt before. Their support is negligible at best, or unnecessary at worst. Harry's base of support is the gay ghetto, not the black ghetto. It is also doubtful that the mayor will open up her campaign coffers to him. She saves them only for herself. Lovely's tepid support will cost her nothing and perhaps disarm one or two Establishment Demagogues.
Bronson is in the pocket of one the mayor's deadliest enemies, slick Joe Morelle pere. Warren can claim that she is building bridges between the two dysfunctional halves of the local Demagogic party.
Which is a lie. Neither faction wants to build bridges. They both wish to destroy the other.
Mayor Warren pissed off the Establishment Demagogues when she refused to endorse Sandra Frankel for Monroe County Executive. She continued to piss them off by not wholeheartedly supporting octogenarian Congresswoman Lulubelle Slaughter in her current bid for re election.
Some people thought the mayor wanted Lulubelle's seat. That was not the case. At least not this time around.
A gesture of sorts to promote party unity was necessary, especially with Mayor Warren running for re election in 2017.
But it is essentially meaningless. Harry doesn't need the Gantt-Warren faction for anything. Not when he has the gay vote on his side.
Who does the mayor think she's kidding? Her cheerleading squad?