Almost four years into his term, the former White House chief of staff has been true to his word. And along the way, he's ticked off enough people to expect, by most accounts, a serious challenge when he seeks a second term early next year.
But at a time when that challenger would be emerging, it's still not clear whether there will be one. Many are wondering whether the nation's most-recognizable mayor is destined to be a one-termer, or just the latest on the path of Chicago mayoral reigns lasting decades, like the two Daleys who preceded him.
"People want to find some reason to vote against Rahm," said Mark Wallace, a talk radio host from the city's working-class South Side who supported Emanuel in 2011 but is now among those he says are "frantically" searching for a replacement.
The leading contender appears to be Emanuel's most outspoken antagonist, Karen Lewis, the Chicago Teachers Union president who went toe-to-toe with him during a 2012 teachers strike.
The blunt-talking Lewis doesn't miss a chance to take shots at Emanuel, saying he acts "like a tourist" in a city he doesn't understand. She's expected to begin circulating petitions for the February election in late August, but isn't saying when she'll decide whether to run.
It's not just Emanuel's decision to close 50 schools in predominantly minority neighborhoods and slash city workers' pensions, or the gun violence plaguing some areas. It's the way Emanuel has done things - with what some describe as a certain Rahm-knows-best arrogance and refusals to answer questions - that has some people wanting him gone.
Labor unions complained they were blindsided when the mayor - who admits he's impatient - went to the state Capitol shortly after taking office to push major changes to city pensions without first discussing it with them.
"There is a lot of antagonism toward Rahm. I don't think there's any question about that," said Don Rose, a longtime Chicago political analyst.
Emanuel insists he's focused on running the city, not on who's going to run against him or recent polls that suggest he's vulnerable.
"When the campaign season comes and there's a campaign time, I'll then focus on the polling and the politics associated with that," Emanuel said.
The mayor's supporters, like Illinois Senate President John Cullerton, who has known Emanuel for years, says the friction was inevitable.
Emanuel inherited huge financial problems from both the recession and his predecessor - including multimillion-dollar budget shortfalls and the worst-funded public employee pensions of any major U.S. city.
Cullerton pointed to Emanuel's success in extending the school day for students in the nation's third-largest school district and helping broker a deal with state lawmakers to address the problems in two of the city's pension systems.
"He is passionate about the city," Cullerton said. "I think he's done a good job."
Under his leadership, Chicago has also come out from under decades-long monitoring to prevent patronage. In recent weeks Emanuel pushed to raise the city's minimum wage to $13 per hour, which could help endear him to Chicago's working class.
Across the city, Emanuel still has star power. On a recent weekday, several 20-somethings waited outside a downtown hub for technology startups where the mayor was speaking in hopes of getting a picture.
"He's trying to reinvent the city in a way," said Brian Parker, 25, noting Emanuel's efforts to make Chicago a high-tech center of the Midwest.
But his drive to get things done - a quality that served him well in Washington backroom deal-making - sometimes comes across as aloof.
On the day his hand-selected school board approved a series of school closings for budget reasons, Emanuel was on a ski trip with his family. His administrators have rebuffed questions, even from city council members, about a red-light camera system suspected of issuing thousands of questionable tickets, many in low-income neighborhoods.
The perception, said Wallace, is that "Rahm does not care about anybody who does not have money."
Said Lewis, who blasted his school funding reductions, "These offices are not entitlements. I think he has to go."
However, Emanuel, a former Democratic congressman, is a fundraising powerhouse whose bulging campaign fund and solid business backing is helping deter possible challengers. The fund had more than $8 million at the end of June, and a separate pro-Emanuel political action committee recently raised $1 million in less than a week.
It's too early to tell whether the anti-Rahm sentiment will be enough to overcome that.
If Lewis runs, Rose said, "It's going to be one tough campaign."