When Mayor Bloomberg was running for re-election he refused to go to Madison Square Garden because the arena’s corporate owner, Cablevision, unleashed a $30 million campaign against his proposed football stadium on Manhattan’s West Side.

Last week, the mayor attended a Knicks-Timberwolves game with his daughter, Georgina, to celebrate her 23rd birthday.

At halftime, Mr. Bloomberg had a brief but cordial conversation with his longtime adversary James Dolan, the head of Cablevision, who came over and shook hands with the mayor.

The decision to return to the World’s Most Famous Arena is not the only example of the mayor burying campaign hatchets since sailing to reelection in November. In the last week, he has quietly diffused several tense relationships.

On Martin Luther King Jr. Day he went to the Reverend Al Sharpton’s New Canaan Baptist Church in Harlem and three days later he stood with union leader Dennis Rivera to promote tax credits for low-income, working New Yorkers.

Rev. Sharpton and Mr. Rivera both endorsed Mr. Bloomberg’s Democratic challenger, Fernando Ferrer, and were two of his harshest critics during the campaign.

Mr. Sharpton was the Ferrer camp’s chief ambassador in attacking the mayor for skipping a debate at the Apollo Theater. Mr. Rivera, the president of the state’s largest health care union, attacked him for putting his endorsement of Mr. Ferrer in question by suggesting his backing was for sale.

“If Bloomberg wants our votes, why won’t he come to our neighborhood and answer our questions?” Rev. Sharpton said in a radio advertisement in the fall.

Now relations between the reverend and mayor, who were on good terms before the campaign, appear to be back on track.

Yesterday, Mr. Sharpton said that while he disagrees with the mayor on some policies, he respects him for attending his King Day gathering.

“I think it’s a mature way of being mayor,” Mr. Sharpton said in a telephone interview. “He realizes the campaign is over and he has got to continue to govern.”

Mr. Bloomberg has gone to the church every year since taking office. Mr. Sharpton said he told him, “‘I did everything I could to make sure you didn’t come back as mayor, but you’re coming back as mayor again.’ We both kind of laughed, and he came.”

Political observers said they are not surprised by Mr. Bloomberg’s olive branch approach.

“He believes there are no permanent enemies,” a professor of public affairs at Baruch College, Douglas Muzzio, said. “There may be opponents on specific issues, but there are no enemies.”

The approach, Mr. Muzzio said, serves the city well because it doesn’t penalize players from partaking in public policy debates simply because they didn’t support the mayor politically.

Deputy Mayor Dennis Walcott said the mayor has had a “consistent record” of working with people even when he disagrees with them.

“I think what you’re seeing now is no different than what you saw really in the first four years of the administration,” Mr. Walcott said.

Mayor Koch – who by his tally has been a candidate in 23 elections – said that when a campaign is over “you want to rise above it and go back to the comforting relationships you had before.”

“Whether it’s Al Sharpton or Dennis, they are very important people,” Mr. Koch said. “I’m sure there are a lot of others that he reached out to that we’re not even aware of.”

Mr. Bloomberg’s relationship with Mr. Dolan was, perhaps, the fiercest. Recently, however, there have been reports that Mr. Dolan is looking to patch things up. With the mayor in office for four more years, that makes sense. But until Mr. Bloomberg showed up at the game it didn’t like there was anything close to a thaw.

“I enjoyed seeing the mayor at the game, it’s always an honor to have him at Madison Square Garden and I hope he comes as often as possible,” he said yesterday through a spokesman.

Mr. Rivera also downplayed his disagreements with the mayor and praised his promotion of tax credits.

As Rev. Sharpton said, “One thing you learn in politics is that you’ve got to govern. You’ve got to keep going. If you hold grudges in politics and you’re not mature enough to keep moving you’re in the wrong business.”