Hours after a midnight deadline passed, Chicago public school teachers headed not for the classroom, but for the picket lines.

　　It was the first time in 25 years that teachers have struck the nation's third largest school system and it came after five months of negotiations over pay and health benefits and over tying teacher performance to student results on standardized tests.

　　Late last night, the talks involving 26,000 teachers and support staff broke down.

　　KAREN LEWIS, Chicago Teachers Union: This is a difficult decision and one we hoped we could have avoided. We must do things differently in this city if we are to provide our students with the education they so rightfully deserve.

　　JEFFREY BROWN: Mayor Rahm Emanuel had a very different view today, as he talked to students on Chicago's South Side.

　　MAYOR RAHM EMANUEL, D-Chicago: I believe that what has been discussed over the last 100-plus meetings over five months, over 400 hours, is an agreement that is an honest compromise. This is, in my view, a strike of choice. And it's the wrong choice for our children.

　　JEFFREY BROWN: The strike left nearly 400,000 pupils in limbo. And officials plan to open 140 schools for half-days to feed those who get free breakfast and lunch. But some of the parents arriving at those schools today were anything but happy.

　　GLADYS HAMPTON, parent: How dare you guys stop school in session? How dare you do that to our children? What are you thinking about? Not about them.

　　JESSE SHARKEY, Chicago Teachers Union: I'm a parent myself. And we recognize how hard this is for parents. And we're working as hard as we can to solve the issues of the schools, so that school can open.

　　JEFFREY BROWN: When that might happen remained unclear. The talks between the union and the city resumed today.

　　The Chicago strike also found its way into the presidential campaign today. Mitt Romney blamed the teachers union and accused President Obama of siding with it. White House spokesman Jay Carney rejected that and said the president was urging a quick settlement. And Mayor Rahm Emanuel, a former White House chief of staff, said he didn't give—quote—"two hoots" about comments trying to embarrass the president.

　　Eddie Arruza has been following the strike for "Chicago Tonight" at public broadcasting's WTTW. And he joins us now.

　　Eddie, first help us to understand what this is all about. What are the key issues here?

　　EDDIE ARRUZA, WTTW: Well, Jeff, it's rather unusual that a strike is not about compensation, but it appears that that is one issue that both sides are very close to agreeing on.

　　The mayor says that the city is offering 16 percent over the next four years, but the key issues that the board—that the teachers union president says are most at play are teacher recall—that is, laid-off teachers being hired back—and teacher evaluations.

　　Now, the teachers union president says that too much emphasis is being placed on standardized test results, and that in many schools throughout Chicago where students have a lot of difficulties outside of school that test scores do not always result in a fair assessment of how teachers are doing.

　　JEFFREY BROWN: Just give us a little bit of context here. Is there the history of tension or—there has been a lot of experimentation in Chicago over the years. How did this—how did we get to this point?

　　EDDIE ARRUZA: Well, as some may know, about 17 years ago, 1995 or so, the former Mayor Daley, Richard M. Daley, took over control of the schools.

　　And for the most part during his tenure, up until last year, he kept peace with the union, the teachers union. And there were a few times when there was a lot of disagreement. But the schools always started on time.

　　Last year, when Mayor Rahm Emanuel took office, he was instrumental in passing state legislation to reform schools. And among the issues that the state approved was how much control principals and the Chicago Board of Education would have over schools.

　　They also changed ways in which the teachers union could bargain, negotiate, for their contract. And so that is what is at play this time around.

　　JEFFREY BROWN: Well, you mentioned Rahm Emanuel. You have got some large personalities in play there, I guess. He comes with a national attention already.

　　He, of course, was involved with some of these issues when he was at the White House. And then you have the teachers union chief, Karen Lewis. Tell us about—is it a personality clash?

　　EDDIE ARRUZA: Well, it doesn't seem to be a personality clash, but these are two very strong-willed people.

　　Many people know Rahm Emanuel as the former White House chief of staff. There is a legendary story about him sending a rival a dead fish in the mail. There's also a story of him accosting a congressman in the congressional locker room, in the showers, no less, to try to convince him to change his vote.

　　And then we have Karen Lewis, who is also a larger-than-life person. She has been very successful in rallying her membership behind her and their cause.

　　And in terms of how the two get together, they have met behind closed doors. And Karen Lewis once said that he—the mayor was pretty assertive with her, even using a profanity towards her, but at the end of their meeting, they—she said that they hugged and that all was well after that.

　　But we have two very strong personalities, Rahm Emanuel, who wants things done his way, and Karen Lewis, who is fighting for her 26,000 members.

　　JEFFREY BROWN: So, what is the atmosphere then today? How is the city, how are citizens responding?

　　EDDIE ARRUZA: Well, we heard in that piece one parent who was less than happy with how things are developing today.

　　But it seems that there is a lot of support for the teachers among parents and among the community. At this hour, there is a huge rally in downtown Chicago, mostly of teachers. Thousands of teachers have taken to the streets right outside the Chicago Board of Education to march through downtown Chicago.

　　There are rolling street closures as we speak. But at the same time, the negotiations have continued on this first day of the strike. Both sides were back at the bargaining table as of 11:30 this morning. They are still at it today. Whether they can reach a consensus tonight and have schools back in operation tomorrow, we will just have to wait and see.

　　JEFFREY BROWN: And, Eddie, just very briefly, is there a sense there—because these fights have gone on around the country—is there a sense that others are watching and waiting to see what the outcome will be?

　　EDDIE ARRUZA: Definitely.

　　This strike is making national headlines. And there are a lot of school districts that, in these tough budgetary times, are looking to see what the outcome of this standoff here in Chicago will be, especially when it comes to teacher evaluations and how teachers—how schools and school districts can control the teachers that are hired and fired.

　　And so there's a lot at stake here, not just here for Chicago, but for many other school districts around the country.

　　JEFFREY BROWN: All right, Eddie Arruza of WTTW, thanks so much.

　　EDDIE ARRUZA: Thank you, Jeff.