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“The revolution will not be standardized. The assault on public education started here. It needs to end here.”

-- Karen Lewis, head of the Chicago Teachers Union, speaking at a downtown Chicago rally where thousands of the organizations’ members protested proposed changes to teacher evaluation and tenure policies.

In America’s third-largest school system, union sentiment runs very strong, and not just among the more than 30,000 teachers, administrators and support staff workers who are now in their third day on strike.

A poll of registered Chicago voters found support for the strike running at 47 percent compared to 39 percent opposed. The survey, conducted by McKeon & Associates, the firm run by Mike McKeon, longtime pollster to former Republican House Speaker Dennis Hastert, found broad-based support across racial and economic lines.

Chicago is union territory, and if there’s any big city where teachers could sustain a strike, it’s this one. Remember, it took non-union Wal-Mart years of cajoling to get a store inside the city limits.

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Of course, even Woodie Guthrie might lose his union ardor given enough days with his kids stuck at home. What seems like a thrilling exercise of people power today might look very different a week from now.

About 350,000 of the district’s more than 400,000 students have been shut out of class. The district has opened some half-day emergency schools staffed by head-office administrators to take some of the pressure off, and there are hot lunches available for students in poor neighborhoods.

But for most parents, this means missed days at work, alarmingly idle children and lots and lots of logistical headaches. The undecided 14 percent in the poll will feel a strong incentive to side against the strike if the pickets continue.

But for now, Chicago stands with the teachers’ union.

It’s been a long time since the district saw a strike, in part because of the Democratic and union dominance in city government. It’s been more than 20 years since teachers walked out. They prevailed, then subsequently won a series of negotiating battles in the following years. With an average salary of $75,000, gold-plated benefits and a fast track to tenure, Chicago’s teachers are accustomed to getting their way.

This time, though, the strike isn’t about getting more, it’s about preventing changes to the rules that prevent teachers from getting sacked.

These changes are modest compared to what many districts have enacted and follow along after years of reform efforts by former schools boss and current Secretary of Education Arne Duncan.

After 10 months of negotiations, though, the issue of how easy it is to evaluate teachers and fire failing ones has become a seemingly impossible sticking point. Even with a big raise on offer, the union, a chapter of the AFL-CIO,  is nowhere close to budging.

There are always national politics at play in a big-city or statewide teacher strike, but that’s especially true here. President Obama is a Chicagoan and while his children are privately educated, some of his neighbors send their children to public schools.

And the man being cast as the villain in this play by the union, Chicago Mayor Rahm Emanuel, is Obama’s former White House chief of staff. While true-blue Emanuel is hardly the Scott Walker the union is describing, he is at odds with the most important part of the president’s political base: government worker union members.

So far, Obama has stood silent on the subject. Duncan has issued a statement calling for constructive compromise, but that’s just boilerplate. If the strike continues, Obama will feel mounting pressure to weigh in. Unlike other local-level controversies in which Obama could have been excused for staying above the fray – the arrest of Henry Louis Gates, the shooting of Trayvon Martin or the Wisconsin labor protests – Obama is a player in this game.

One assumes that even as the White House tries to deal with the deadly anti-American riots in the Arab world, a sputtery economy and rising fuel prices, somewhere, somebody on Team Obama is trying to get this resolved before the president has to weigh in.

There are considerable upsides to the president joining the fray.

One of the best policy points for the president with voters is the efforts he and Duncan have made to add some elements of meritocracy to public education. Their Race to the Top program doesn’t offer the stick to lousy teachers but does reward schools that increase standards and performance.

If Obama were to call for teachers to return to work and accept the new requirements proposed by Emanuel’s administration,  it would play very well with the suburban mothers who will likely decide the election. Those voters are very concerned about the country’s crumbling public education system and might be gratified to see Obama take a stand against teacher unions.

However popular teacher union are in Chicago, they have fallen into disrepute nationally. The crusade for accountability and flexibility in union rules has become a national concern as in the film “Waiting for Superman.”

If Obama were seen standing up to his political benefactors in the government unions, he would have a chance to change public perceptions about him and his administration. To further abuse a much-overused phrase, it could be a “Sister Souljah moment.”

But Obama is counting heavily on the money and ground troops of government unions to prevail in November. The incremental efforts at reform by his administration were already unpopular with this most-important Democratic bloc. Voicing disapproval for a strike that union members see as a principled struggle would be very costly.

If he speaks out in favor of the strikers, even in tentative terms, Obama would look like a captive of his base. If he speaks out against them, even tentatively, he risks further exacerbating the wide enthusiasm gap with Republicans this year.

The best hope for Obama is that the storm passes quickly and he isn’t forced into the fight. That’s why you can be sure that the efforts behind the scenes in Obamaland to get this strike ended are intense.

Chris Stirewalt is digital politics editor for Fox News, and his POWER PLAY column appears Monday-Friday on FoxNews.com. Catch Chris Live online daily at 11:30 am ET  at live.foxnews.com