After weeks of planning for it, talking to people about it, and finding voters who support it, Cook County Sheriff Tom Dart said he was convinced of two things: He could be the next mayor of Chicago _ and the price he would have to pay wasn't worth it.
"I think I could be a great mayor," Dart said Wednesday, announcing he would not join the race to succeed the retiring Mayor Richard Daley. "The question is at what cost."
His surprise announcement that he would not run for a job he clearly wanted _ after telling many people that he was running _ involved a complex calculation about his family and taking on the monumental task of mayor at a time when the city is in dire financial straits.
Dart insisted it was primarily about his children and not, as some speculated, about his odds in a tough and costly campaign against former White House chief of staff Rahm Emanuel and others.
His decision threw another twist into the wide-open race. Dart had been seen as a leading contender and had ranked at the top of a number of polls, despite the fact that he was not officially campaigning.
Asked if he thought his move cleared the way for Emanuel, Dart said, "I don't think I'm paving the way for anybody." Among the others in the race or preparing to run are City Clerk Miguel Del Valle, former Chicago school board president Gery Chico and former Sen. Carol Moseley Braun.
Dart said he became aware of just how much running for mayor and holding the job would cost him and his family in the last six weeks or so, when he wouldn't see his five children awake for days at a time and when he did see them he told them he'd see them again soon, knowing that was "a lie." They range in age from 1 to 9.
"If I ever had to look myself in the mirror and said I put politics ahead of my children I would never forgive myself," he said. "That's the one thing I couldn't live with."
The sheriff also said he got a glimpse of what his life would be like as a candidate and as the mayor when one of his children begged him not to leave the house.
"My 7-year-old got very upset a couple of nights where she was literally clinging to the door and crying hysterically, didn't want me to leave," he told The Associated Press after the news conference. "That resonated with me."
Dart, who has made national headlines with moves such as suing Craigslist, halting foreclosure evictions and leading an investigation into an alleged scandal at a historic black cemetery, also acknowledged that part of his decision was based on how difficult a time the next mayor will have.
"Given the financial issues facing the city, no one in good conscience could go into it without saying 16 hours is the norm here and the weekends will be no different than the weekdays," he said.
Emanuel dismissed the notion that Dart did not want to take him on, saying the ambitious Dart would never be "scared" out of a race for office.
"I don't think you can scare Tom Dart away," Emanuel said. "I think you really have to respect him, as you know he's very committed to his family, he loves this city, he loves his job. ... Tom Dart does not get scared. I think he made a personal decision and evaluation. I think he is a man of his word."
Those around Dart had been convinced he was going to run _ in large part because Dart told them in no uncertain terms he wanted to be mayor.
"I've talked to political people and the like over the course of the last five weeks saying 'I'm going to run, I'm very serious about running, I'm going to do this,'" he said.
While Dart repeatedly said the reasons begin and end with his family, some political observers wondered if other calculations didn't enter into his decision.
Dart, after all, has been involved in Democratic politics in Chicago, helping others run for office and running himself. Surely, they say, he knows the toll public life takes on a person's family. And, they say, he's known it for longer than the weeks he's been privately telling people he was going to run.
"It's one of those universal excuses you hear for backing out of something: 'I want to spend more time with my family, I want to be a better parent,'" said political analyst Don Rose. "In some cases it's accurate, but it is cause for skepticism."
But, he said, Dart appears to be someone capable of walking away from a campaign he had a real shot at winning for his family.
One possible explanation is that Dart knows of a poll that showed winning would be difficult or that he heard that other prominent politicians who have not yet come forward are poised to enter the race. Rose, for example, pointed to his own recent blog in which he wrote that if Attorney General Lisa Madigan decided to run, with the help of her father, the powerful Illinois House speaker, Michael Madigan, she would win.
"If she gets in the race it's likely Dart might wind up not running," Rose wrote. "I suspect he is counting on having Speaker Mike Madigan's invaluable support for mayor, but obviously not against Lisa."
Madigan has said she has no plans to run, but at times had declined to answer questions about whether she would serve out a full term if re-elected to her state job next week.
Dart said there were no political considerations other than what he knows about politics and the toll it takes on people's personal lives.
"How can I, three years from now, four years from now say to my kids, I didn't know I wasn't going to be around (for his family) when I knew exactly that it was going to happen." he said.