Rep. Charles Rangel’s wife will introduce C. Virginia Fields at her big Women for Fields Kickoff Mayoral Breakfast tomorrow morning.

Political strategists said an introduction by Alma Rangel is another sign that the dean of the New York congressional delegation will endorse the Manhattan borough president in her quest for City Hall.

“Whether he’s there or not, it sends a signal that Virginia is his candidate, he thinks she’d be a great mayor,” a political consultant, Hank Sheinkopf, said. He said a Rangel endorsement would be a coup for Ms. Fields, especially since her leading Democratic opponent, Fernando Ferrer, won Mr. Rangel’s endorsement in 2001.

“The Rangel name is very important citywide,” Mr. Sheinkopf said. “It brings a certain amount of prestige. It brings the perception of political muscle, and that’s important in a mayoral race.”

Other political experts said that if Mr. Rangel had decided to back Ms. Fields for mayor, he would be standing beside her at the breakfast with his wife, who is one of the founding members of the Congressional Black Caucus Spouses.

Political consultant Mike Paul, who was an aide to Senator D’Amato and an economic development official in the Giuliani administration, said Ms. Rangel’s presence could be a “trial balloon.”

“Someone like Rangel might be saying to more than one person, ‘Prove to me that you deserve my endorsement,’ ” Mr. Paul said. “Gatekeepers like that like to be with a winner.”

A Baruch College professor of public policy, David Birdsell, said New Yorkers shouldn’t read too much into Ms. Rangel’s introduction at the fund-raising event since husbands and wives have been known to disagree, especially on politics.

In the past few weeks, Mr. Rangel has repeatedly praised Ms. Fields publicly but has not said whether or when he would endorse her.

A consultant for Ms. Fields, Joseph Mercurio, said Mr. Rangel’s is one of the few important endorsements in town.

“Most of the endorsements of elected officials have no impact. Very often, elected officials will roll out a million endorsements,” he said. “But Charlie is a very well-known figure and he has a tremendous amount of influence inside the black community. African-American voters look up to him and care about what he’s doing, as do other voters.”

He said donors also tend to give money to the candidates Mr. Rangel endorses.

Mr. Mercurio said he has met with Mr. Rangel but doesn’t know if the congressman will endorse Ms. Fields. He said the two officials’ having worked together over the years, as they have represented the same district, does not guarantee her an endorsement.

“She’s not his protegee. It doesn’t work that way really,” Mr. Mercurio said. “The Harlem leaders people talk about are a bunch of guys. She was never part of the crew. She’s always been very independent.”

A spokesman for Mr. Rangel did not return phone calls for comment.

About three-quarters of the people who will be attending tomorrow’s campaign event are women. The former governor of New Hampshire and the Kerry-Edwards campaign chairwoman, Jeanne Shaheen, is keynote speaker.