Mayor Daley's decision completely changes the city's political landscape. From the city council alone, there could easily be a half dozen or more candidates for mayor.
The proverbial elephant in the room, however, is White House Chief of Staff and former Chicago-area congressman Rahm Emanuel, who in April caused a stir by merely mentioning his interest in someday serving as Chicago's mayor.
The Chicago City Council Finance Committee was in the midst of a hearing on funding O'Hare expansion Tuesday afternoon when the news came down that Daley had decided not to run again.
The dean of the City Council, Ed Burke, looked out at his fellow aldermen and said, "Wow! So all you wanna-be mayors, I guess you'd better run out and get your petitions."
It will not be long until some of them do. In the two decades that Daley served as mayor, there have been many wanna-bes who have held their ambition in distant orbit.
After Tuesday's blockbuster, it may be time to break out the scorecards.
"We're gonna look at the numbers now and our exploratory committee will determine in the next few days whether we're gonna run or not," said 32nd Ward Ald. Scott Waguespack.
"I've been urged by a number of people: constituents, labor people, businesspeople, to run for mayor, and in the next ten days I will be making a decision after I meet with them again in this new development," said 2nd Ward Ald. Bob Fioretti. "I've been making a lot of phone calls in the last two hours and we'll see what happens."
27th Ward Ald. Walter Burnett, Jr. said that he would like to see "either an African-American run for mayor of the city of Chicago, or a candidate run with the African-American community interest at heart."
"We want to see a candidate who can run the city of Chicago continuously to bring people together, continuously to build our city, which is a ubiquitous city - we want to keep building that around the country where people can understand that Chicago has a lot of good people who can run it," said 48th Ward Ald. Ed Smith.
Asked whether he would be running for mayor, Smith said: "Let me say that I want to be a person who can do a job the way it has to be done. I've done it in the city council - I want to continue to do that. I have not thought about whether I want to be mayor or not."
25th Ward Alderman Danny Solis said that he thinks Daley "is the best mayor Chicago ever had, including his father."
The aldermen did not see it coming - even those who work somewhat closely with the mayor.
"I'm frankly shocked - I can't think of anybody who would be better able to lead the city in these challenging times," said 14th Ward Alderman Burke.
Burke did not rule out a possible run for mayor on Tuesday.
"It's just shocking," 31st Ward Ald. Ray Suarez said of Daley's announcement. "I mean, I couldn't believe it."
45th Ward Ald. Pat Levar shared Suarez's surprise.
"It was a shock," said Levar. "I didn't know anything about it."
The mayor's decision had many aldermen taken aback, taking at least a moment to survey the altered political playing field.
"I actually have to process all of this," said 42nd Ward Alderman Brendan Reilly. "I wasn't planning on it; I was planning on running for re-election, but with this, you have to take a look."
"We're ready to convene a meeting A.S.A.P.," said 27th Ward Alderman Walter Burnett.
Burke, considered the "dean" of the city council, suggested that he might even ask Richard M. Daley to reconsider, and stay on, but he knows that will not happen. After 21 years, the decision is final, leaving Burke and other aldermen looking at their options.
"Most of the people who would think about this are still reeling from the announcement that, frankly, nobody that I know of in politics thought would happen," said Burke.
So Waguespack, the 40-year-old alderman from the 32nd Ward, is likely in the running, and it looks like Bob Fioretti may be as well.
Another possibility is CTA chief and former alderman Terry Peterson. He said "there is plenty of time to discuss" what will happen next.
Cook County Assessor Jim Houlihan's office issued a statement saying, "Assessor Houlihan is interested in being mayor."
Cook County Sheriff Tom Dart is also being mentioned, as is U.S. Rep. Luis Gutierrez. Both made statements regarding Mayor Daley's announcement Tuesday.
"Mayor Daley has become synonymous with Chicago. The mayor is a true Chicagoan in the best sense of the word: he cares deeply for the people of our city and has served them tirelessly," said Gutierrez. "I know Mayor Daley was always motivated by a genuine desire to make Chicago a better place to live."
Gutierrez said he has received many questions regarding his future plans, but he said that he will need to discuss with his supporters and family before making any decisions.
Dart said he was surprised by Daley's decision, and that he recognizes the mayor's contributions to the city. He said he knows that he will be missed.
The sheriff said he is focused on re-election and will only leave that position if he sees an opportunity to have a greater impact on people's lives than his current office.
"Mayor certainly fits that," Dart's statement read.
Other names mentioned Tuesday include Jesse Jackson, Jr. and Rev. James Meeks.
The last time that a sitting mayor opted not to run for re-election was 1947.
In addition to submitting 12,500 signatures and not owing any money to the city, a candidate must have been a Chicago resident for one year.
Petition signatures may already be gathered, and November 15 is the first day that mayoral candidates can file their petitions, an order that determines ballot position.
The filing deadline is a week later on November 22.
Caucuses will now try to get a quick feel for who might best develop money and muscle to rise to the top tier. However that shakes out, aldermen are not forecasting a return to racial divisiveness.
"I don't believe that we'll ever get back to the era of the early 1980s when they called it, I think, 'something by the lake,'" said Ald. Solis.
Chicago was nicknamed 'Beirut on the Lake' during the 'Council Wars' of the early 1980s. Those days are long gone, several aldermen said Tuesday.
The announcement leaves an open door for White House chief of staff Rahm Emanuel, who said in April during a television interview that "it's no secret" he'd like to run for mayor of Chicago someday.
At the time, Emanuel called Mayor Richard Daley "a dear friend" and said he's done "a fabulous job" as mayor. He said on Charlie Rose's PBS talk show that he hopes Daley will seek re-election and said he'd work for Daley if he runs again.
"But if Mayor Daley doesn't, one day I would like to run for mayor of the city of Chicago," Emanuel said. "That's always been an aspiration of mine even when I was in the House of Representatives."
On Tuesday, Emanuel issued this statement from the White House: "While Mayor Daley surprised me today with his decision to not run for reelection, I have never been surprised by his leadership, dedication and tireless work on behalf of the city and the people of Chicago."
The 50-year-old Emanuel is a one-time Daley adviser and a Chicago native. He was an Illinois congressman until he resigned to take his current White House post. A few days later, Daley said the two are friends but didn't endorse Emanuel as his heir apparent. "I think there are many people out there who would be great mayors," Daley said.
Emanuel still owns a home in Lakeview, despite working full-time for President Obama in Washington.
Residency, which according to the Chicago Board of Elections is a filing requirement for becoming a candidate, will apparently not be an issue for Emanuel.
Emanuel is still a registered voter in Chicago, and he voted as a resident of Chicago in the Illinois primary 7 months ago.
Political consultant Don Rose on Tuesday said he felt that Emanuel and Cook County Sheriff Tom Dart "would be at the top" of his list of possible candidates.
"Assessor Jim Houlihan, I think, might get into that mix," said Rose.
Of course, there are yet more names being bandied about as possible successors to Daley - a few are currently in non-elective positions and others in business.