Mayor Bloomberg seems to think that even if leaders publicly endorse his Democratic opponent, they will actually cast their ballots for the incumbent on Election Day.

When asked yesterday about Rep. Charles Rangel’s decision to endorse Fernando Ferrer, the mayor suggested that a public declaration of support – at least for another candidate – would not necessarily translate into a vote.

“In my heart I always think that the people that give the endorsement to somebody else, in the end, in the voting booth, will probably be voting for me – at least I hope so,” Mr. Bloomberg told reporters before marching in the Mexican Day Parade.

When told of the comment later in the day at the African American Day Parade uptown, Mr. Rangel, who announced his endorsement yesterday, called it “ridiculous.”

“He’s got to stop drinking,” said the congressman, who was marching with Mr. Ferrer but has had a good relationship with the mayor. “I’ve never heard anything that silly in my political life.”

“If that’s his expectation, I believe it’s a vain one,” Mr. Ferrer said when asked about the mayor’s remarks. “And if that’s his hope, well, what can I say? Hope springs eternal.”

Mr. Ferrer emerged as the Democratic Party nominee last week after Rep. Anthony Weiner, who received the second-most votes in the primary, dropped out of the race even though Mr. Ferrer missed the 40% vote total needed to avoid a runoff. Reports over the weekend suggested that Mr. Ferrer, a former president of the Bronx, would meet the 40% requirement once outstanding paper and absentee ballots were counted. The Board of Elections expects to have a finally vote tally by tomorrow.

The Reverend Al Sharpton, who endorsed Mr. Ferrer days before the primary, called Mr. Bloomberg’s comment “insulting” and predicted that the mayor would lose votes “if he continues to be that arrogant.”

“We respect the people that are supporting him, and he ought to respect the people that are not supporting him,” Rev. Sharpton said. “I think it’s absolutely insulting to tell us that we are not going to do what we say.”

A political consultant, Hank Sheinkopf, said: “There will be a lot of Democrats who will say yes to Ferrer publicly and then vote for Bloomberg. I’m not saying Charlie Rangel is one of them.”

A professor of political science at Baruch College, David Birdsell, had a different take, saying that while it would be difficult for an elected Democrat to cross party lines and endorse the mayor, there was no reason to second-guess their public declarations.

“It misrepresents the good-faith declarations of public officials,” he said. “What we do have to do is look at how vigorously they put muscle on the street behind their endorsements.”

In July, after the city’s largest municipal union, District Council 37, endorsed the mayor, a spokeswoman for the Ferrer camp, Jennifer Bluestein, suggested that rank-and-file union members would vote for her candidate anyway. “Freddy Ferrer will have their support on election night,” she said.