Mayor Bloomberg stopped into a Harlem IHOP yesterday morning, but not for a tall stack of pancakes. He was there for something far weightier.

One of New York’s most influential black leaders, the Reverend Calvin Butts, the pastor of Harlem’s historic Abyssinian Baptist Church, stood with Mr. Bloomberg in the restaurant yesterday morning to announce he was endorsing the mayor for re-election.

During the campaign leading up to the Democratic primary, Rev. Butts threw his support behind the Manhattan borough president, C. Virginia Fields, who is a member of his congregation. At the time, he said that if she didn’t win the nomination he would support Mr. Bloomberg in the general election. He didn’t wait 48 hours after Ms. Fields lost to throw his arm around, and his support behind, the Republican incumbent.

“We are just happy with his performance thus far in our city,” Rev. Butts said, standing beside the mayor. “I hope all New Yorkers will vote for him.”

The state Democratic Party claimed the endorsement wasn’t big news since it wasn’t the first time the pastor praised Mr. Bloomberg, but it was difficult to brush aside the endorsement, which cuts into the “black-Latino coalition” that Fernando Ferrer is trying to forge.

“He makes it appear that Ferrer does not have the unity that Ferrer says he has,” a veteran political consultant, Hank Sheinkopf, said. “What the Bloomberg campaign wants to do is tactically remove large portions of the normal Democratic vote away from Fernando Ferrer.”

The consultant said that Rev. Butts’s endorsement won’t win the election for Mr. Bloomberg, but he called it “significant” and said it could work to counteract the impact of the Reverend Al Sharpton’s endorsement, which went to Mr. Ferrer on Sunday.

Rev. Butts said he thinks Mr. Ferrer will have an uphill battle building a coalition of black and Hispanic voters.

“Mr. Bloomberg has made a considerable dent in the black community and Latino community,” he said.

While Mr. Bloomberg was waiting for the pastor to arrive, he walked around the restaurant, mug of coffee in hand, greeting diners and sometimes sitting to chat with them. The patrons greeted Mr. Bloomberg warmly but expressed a range of opinions on his mayoralty.

Rashida Snead, who was eating a burger and fries, said she voted for Ms. Fields on Tuesday and expects to vote for Mr. Ferrer in November.

“He’d be more geared to put an end to the contract situation for teachers,” Ms. Snead, 27, whose mother has been a teacher for 30 years, said. She said she’d change her mind if the contract dispute is resolved.

A bus driver for the MTA, Henry Covington, said he’s still deciding between Mr. Bloomberg and Mr. Ferrer.

“I want to find out everything Ferrer stands for and put one against the other,” he said.

A tenant specialist, Marilyn Foulks, 56, said she didn’t vote in the Democratic primary. “I’m saving my vote for Bloomberg,” she said.

Speaking of Mr. Ferrer, she said: “I don’t think he could do the job, even though he’s a Democrat and I’m a Democrat.”