CHICAGO (CBS 2) — Rahm Emanuel has officially stepped down as White House chief of staff as he prepares to launch his campaign for mayor of Chicago.

Although he did not specifically mention the mayoral race as he stood with President Barack Obama in the East Room of the White House, Emanuel said he was “energized by the prospect of new challenges and eager to see what I can do to make our hometown even greater.”

Reports of Emanuel’s departure from the White House have been spreading ever since Mayor Richard M. Daley announced last month that he would not be seeking re-election. The president called Friday’s announcement “the least suspenseful announcement of all time.”

Obama thanked Emanuel for his service as chief of staff, saying “we could not have accomplished what we’ve accomplished without Rahm’s leadership.”

The president also avoided any direct mention of Emanuel’s mayoral ambitions, though he did say Emanuel is “extraordinarily well-qualified” for his next challenge.

“He has been a selfless public servant. He has been an outstanding chief of staff. I will miss him dearly,” Obama said.

Sources familiar with Emanuel’s plans said that a viral internet ad featuring Emanuel will be put out over the weekend, making it clear Emanuel he is running for mayor of Chicago.

On Monday, Emanuel will begin meeting with voters all across the city as he ramps up his campaign. It is not clear when or how he plans to make a formal announcement of his campaign.

“This is a bittersweet day for me,” Emanuel said. “On the one hand, I’m excited to be heading home to Chicago. … I’m energized by the prospect of new challenges and eager to see what I can do to make our hometown even greater.”

Emanuel choked up and wiped away tears as he talked about his father and grandfather, both Israeli immigrants.

“My father and my grandfather came to this country for opportunity. They came here for a better life for their children. My mother marched with Martin Luther King because she believed none of us is truly free until all of us are,” Emanuel said. “Both my parents raised me to give something back to the country and the community that has given us so much.”

Emanuel’s plans have been the source of widespread speculation both in Chicago and Washington, D.C. ever since Daley announced he would not seek a seventh term in office. In an April television interview, Emanuel had called it “no secret” he’d like to run for mayor.

“That’s always been an aspiration of mine, even when I was in the House of Representatives,” Emanuel told Charlie Rose.

Daley, who has held the mayor’s job since 1989 and carried on a family dynasty, surprised many with his announcement. The choice for Emanuel suddenly became whether he would make a dash for the political job he has openly coveted, at a cost of uprooting his family again and quitting his post of national influence sooner than he thought.

When he ultimately announces his candidacy, Emanuel instantly becomes the most recognizable name in what is already a crowded field of candidates and possible candidates. Already with well over $1 million in his war chest and his well documented ability to raise huge amounts of money for political candidates around the country, Emanuel”s campaign would be extremely well-funded.

Other possible candidates include Cook County Sheriff Tom Dart, who has made a name for himself in the Chicago area for suing Craigslist, among other things; former U.S. Sen. Carol Moseley Braun; State Sen. Rickey Hendon (D-Chicago) and Chicago Ald. Bob Fioretti (2nd).

Emanuel’s decision “really isn’t going to impact anything I do,” Dart said Thursday.

City Clerk Miguel del Valle — one of two formally announced Hispanic candidates for mayor — said the more the merrier, provided candidates are ready to talk about issues.

A number of African Americans besides Moseley Braun and Hendon are considering running, including U.S. Rep. Danny Davis and James Meeks, a state senator and prominent black minister. Black ministers, politicians and others have discussed throwing their support behind a single candidate.

A number of possible candidates, including Moseley Braun, Davis, Meeks and Dart, are in the process of collecting the 12,500 signatures necessary to win a spot on the February ballot.

Those running against Emanuel are sure to label him an outsider, and Emanuel will counter by stressing his ties to the city, particularly his tenure in Congress representing the district that includes Chicago’s North Side.

Obama himself has said Emanuel would be “a terrific mayor,” but he thought Emanuel would wait until after the Nov. 2 elections before deciding officially.

There have also been some questions about Emanuel’s residency, considering he moved to Washington D.C. with him family almost two years ago. But city officials say he is still registered here and still owns his home. The big questions now seem to be when, where and how will he officially announce his campaign.

Emanuel’s Chicago home is still rented out. He reportedly is still looking for someplace to sleep.

CBS 2 Political Producer Ed Marshall, reporter Dana Kozlov, CBS News reporter Tara Mergener, and The Associated Press contributed to this report.

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