Mayor Thomas M. Menino’s earthshaking decision to bow out of the next election left some at Suffolk Downs concerned about whether Boston’s next leader will be as supportive of its casino plans.

The final votes for the project will be cast before Menino leaves office at the end of the year, but an anti-casino successor could still make things rocky.

“We’re on pins and needles here. We don’t know what’s going to happen,” said a source connected to the racecourse.

A spokesman for Suffolk Downs declined to comment, but pointed to a timeline showing that much of the casino’s approval process will be completed before Menino steps down in January.

State Rep. Marty Walsh, who has said in the past that he will consider a run for mayor, said he believes Menino will see the project through: “That’s part of his plan, to bring an industry to Boston, to bring jobs to Boston. Knowing him he’d want someone to continue that.”

The news of Menino’s departure came as Vornado Realty Trust has decided to divest its 19 percent interest in Suffolk Downs after refusing to submit to background checks required of all casino license applicants.

The state gaming commission approved putting Vornado’s interest in Suffolk Downs into a blind trust until the divestiture is completed so the license bid could move forward, according to a memo from Catherine Blue, the commission’s general counsel.

The memo indicates that out of 14 individuals associated with Vornado, only two filed the required disclosure forms, with another being allowed to withdraw as 
a qualifier.