That amount becomes something of a soft benchmark for those now entering the mayoral sweepstakes.
Other important factors are race, political history and power. Regardless, the candidates' first hurdle is getting 12,500 valid signatures to get on the ballot, and that will be checked by Chicago's Board of Election Commissioners, the office in charge of running the upcoming mayoral election.
"It can seem daunting," said Chicago Board of Election Cmsr. Langdon Neal.
"Daunting" because the chairman of Chicago's Board of Election now expects a record-breaking amount of work for February's city election.
"We have to have extra hearing officers. We have temporary workers. We cancelled vacations and days off. We told our staff that they'll be working pretty much around the clock for three months," said Neal.
And potential candidates - including several aldermen - are already working to raise money.
"I think it will probably take between $4 million and $7 million depending on how crowded the field is," said Ald. Sandi Jackson of the 2nd Ward.
Jackson has 66,000, while State Sen. James Meeks has $71,000.
"To an outsider, it may take more. It depends on the mix of candidates. We may have a candidate like Rahm Emanuel who's real good at raising money, but others who have a base of voters. So, all of that will be in the mix," said Cindi Canary of the Illinois Campaign for Political Reform.
Consider, then, presidential Chief of Staff Rahm Emanuel, who said he'd like to be mayor post-Daley.
Emanuel has just shy of $1.2 million in his campaign fund. He doesn't have a citywide organization, but he knows how to set one up, and he know how to raise money.
Cook County Sheriff Tom Dart has a comparatively small amount in his campaign fund, $243,000, but he's very high profile, and he's got an organization.
Then, there's Ed Burke, the dean of the City Council, who -- after decades as an alderman -- has political baggage. But he's also got a huge war chest: $3.8 million in his campaign fund.
" It would be one of the farthest things from my mind," said Burke, who represents the city's 14th Ward.
" "In Chicago politics, people never close the door," 2nd Ward Ald. Bob Fioretti said.
Congressman Luis Gutierrez, who was expected to return to Chicago Wednesday night and plans to discuss a potential run with his wife, has just over $500,000.
"This is a big TV market. It's going to take going on TV. It's going to take putting up some billboards, doing ome mailing. $4.5 million sounds fair," Canary said.
If there are -- as early interest suggests – 10 to 20 possible candidates, those who can demonstrate fund-raising prowess early on have the ability to scare off some of the others.
"I'm not sure if it should scare them off. In this particular race, it's gonna be about a lot more than who can raise the most money," Canary said. "If there is a lot of support out there, I think someone can run a very strong, very vigorous campaign without having the most money."
So, money isn't everything, but it can play a big role in defining the field, and that's quite important in a campaign that doesn't have much time.