For full coverage of Chicago's teacher strike, click here.

Update: Negotiations failed Sunday and the Chicago Teachers Union went on strike Monday morning.

If Chicago teachers go on strike Monday, the walkout would set up a political minefield for both Mayor Rahm Emanuel and Chicago Teachers Union President Karen Lewis, adding the explosive element of a blame game to contract negotiations that already are highly combustible.

For Emanuel, there's the risk of angering hundreds of thousands of working parents who would suddenly need to find child care, not to mention the relatives who may be pressed into duty. A mayor who is trying to build his reputation as a problem solver leading Chicago into a modern era of streamlined government could see his narrative undercut.

For Lewis, walking out might cement her as a folk hero with the rank-and-file teachers she represents, a leader willing to stand up to a guy she's long branded a liar and a bully. But reaching a deal that validates a strike and allows her to save face could prove challenging -- both sides acknowledge there's not a pile of cash hidden in a safe somewhere from which to draw large raises. "It is your responsibility, President Lewis, and your responsibility, Mayor Emanuel, that children are not where they are supposed to be, and that's in school," said veteran Ald. Carrie Austin, 34th, when asked about the potential political fallout from a strike. "The blame is on both of them there. It gets laid at both their feet."

Whether it's the mayor or the union president who is more light-footed could go a long way toward determining who wins the battle for public opinion should a strike occur. Talks were scheduled to resume Saturday ahead of Monday's strike date.

Emanuel's double-edged sword

Inside the mayor's camp, few thought a strike would become reality, but it's now "more of a concern than a week ago," said an administration source.

If teachers walk out Monday, the mayor's message will probably change. So far, Emanuel has maintained that he does not want to negotiate in public, but if picketing begins, he'll likely openly air his differences with the union.

"We're going to get to the point where it's probably a strength to say what's left, where we're at and where they are," the source said.

Ald. Ariel Reboyras, 30th, said parents he has spoken to recently in his Northwest Side ward have mainly been siding with the teachers. "The teachers union has done a very good job lobbying, getting its message out," Reboyras said.

But if a strike happens, some of the momentum -- at least in the short term -- could swing back to the mayor, a politician known as a master of messaging. The teachers will have been the ones to strike, and the mayor can say that it didn't have to come to this and that it's the children who are bearing the brunt.

Emanuel seemingly has been laying the groundwork to make that argument, in recent weeks responding to reporters' questions about the likelihood of a work stoppage by insisting the focus remain on the students who would be deprived of the full school year they desperately need.

Also on the mayor's side are self-proclaimed education reform groups, which have spent tens of thousands of dollars on radio ads to undercut the union's position. Such ads might reasonably be expected to ramp up in frequency and volume in the event of a strike.

Democrats for Education Reform, an organization started by Wall Street hedge fund managers that opened offices in Chicago this year, staged a protest near union headquarters Friday demanding that the union call off a strike.

Emanuel's approach to education fits with the agenda of a number of his wealthiest political supporters, including Penny Pritzker, a member of the Board of Education, and venture capitalist Bruce Rauner, whose wife, Diana, an early education expert, served on Emanuel's transition team.

The reform groups are expecting to make gains during contract negotiations, and the mayor has to balance that kind of political pressure against a potential backlash from parents.

There is some political hay to be made in casting oneself as the guardian of taxpayers' wallets and taking a hard line on teacher raises. That's especially true at a time when city homeowners are frustrated by rising property taxes even as their home values plummet. To claim victory, Emanuel will have to be able to make the case that a new contract is economically responsible.

Complicating matters for Emanuel is the fact nearly half the students in Chicago Public Schools are African-American, a constituency that strongly supported his mayoral bid and which he now risks alienating if parents see him as the bad guy in a school strike.

"Lots of teachers in Chicago are African-American, which would be a problem, if you are not supportive of teachers," noted Ald. Leslie Hairston, 5th.

Emanuel's administration has pressed forward with plans to change the way city government relates to its large unionized labor force and has done so up to now without subjecting residents to major service disruptions.

Teachers, however, are not like garbage collectors and McCormick Place electricians. Ald. Willie Cochran, 20th, said many Chicagoans regard teachers as members of the family and don't want to see them treated with disrespect.

"Our children are in their hands, and we trust them and support them," said Cochran, whose ward includes parts of the Back of the Yards, Englewood, Washington Park and Woodlawn neighborhoods.

"When you start talking about getting the kind of support across the board from teachers and the teachers union on these issues, then you also bring the parents aboard. The parents are not supportive of a strike or not being in school."

How it cuts for Lewis

At the outset, Lewis and the union found themselves on their heels. Emanuel's school board quickly took away 4 percent annual raises that teachers were due. The mayor also scored an early win last year by pushing through state legislation to lengthen the school day, despite union opposition. Unsatisfied with that triumph, the mayor spent money to get a handful of schools to jump the gun last year and add time to the school day instead of waiting to negotiate.

The move antagonized teachers, giving Lewis ammunition to unify her troops around a common enemy and easily achieve the level of support necessary to go on strike if it came to that. Lewis also got the mayor to cut a deal on his signature longer school day proposal. The district agreed to hire nearly 500 teachers so students can put in a longer school day without extending the workday for most teachers.

Lewis, who 11 months ago made headlines for a series of public gaffes, had rallied.

Did the mayor miscalculate? "Sometimes it's not what you do, but how you do it," Ald. Hairston said.

Lewis, however, can't afford to misplay her hand. It's to her benefit for the public to see teachers as sympathetic characters as the strike drama unfolds. She said Friday that the union has built a strong relationship with parents by listening to their concerns "for a very long time" while school officials have been dismissive.

During a break from negotiations Friday, Lewis said, "No one is victorious in a strike."

"Everyone's going to get fed up if this turns into a long, grinding negotiation," she added. "Let's settle this."

Rod Estvan, education policy analyst for disability rights group Access Living, said national education unions are looking at the CTU's experience as a model to curb attacks on unions.

"This is a big deal, not just in terms of Chicago, but in the national labor movement, particularly following the defeats in Wisconsin. On the national scale, it's the next front line," Estvan said.

Lewis, who has had sharp words about Emanuel, said the negotiations are "not about standing up to the mayor. It's about getting a handle on what public education is, what it's supposed to do."

The union president also said members are realistic about the city's financial situation. "We know this is an austerity contract," she said. "If you don't have the money, the question is, 'What else can you do?'"

In light of the tight budget, Lewis said the union has laid out to city negotiators a "pathway to get back in" if the teachers do strike. She declined to offer specifics.

Lewis can claim victory if a short strike ends with a contract favorable to teachers, according to Dick Simpson, a political science professor at the University of Illinois at Chicago. Lewis could argue the teachers union flexed its muscles and the Emanuel administration caved.

"The problem isn't so much if the teachers strike," Simpson said. "The question is how long they strike and on what terms it's settled."

Potential advantage for either side could evaporate if a strike drags on and parents are forced to miss days of work to care for their children. A worst-case scenario for the mayor would see two of his biggest challenges coming together: more children on the streets during a strike as the Police Department continues to struggle to bring down the homicide rate.

"If it's a short strike, it can be chalked up as a win-win. If it goes longer, it depends on how the public understands the chronology of the strike and who the public assigns responsibility to," said Ald. Will Burns, 4th.

(c)2012 the Chicago Tribune