CHICAGO – Let there be no more doubt about the self-serving nature of teachers unions.

The Chicago Teachers Union has set a strike date of Sept. 10, despite the fact that the students just started a new academic year and the school district is struggling financially.

Chicago Public Schools are nearly $1 billion in debt. Mayor Rahm Emanuel wanted kids to get more crucial instruction time, so he lengthened the school day this year. But the city also agreed to accept the expense of calling back more than 400 furloughed teachers so existing teachers wouldn’t have to work longer days to cover the extra instruction time.

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Yet the leadership of the Chicago Teachers Union is still demanding an outrageous raise. Their initial target was an unheard of 30 percent, and they rejected a third party recommendation for an 18 percent increase. They obviously don’t care that the district is nearly broke, and may have to severely curtail student services to make ends meet.

“We have said from the beginning that we are tired of being bullied, belittled and betrayed,” CTU President Karen Lewis was quoted as saying in a report by the Huffington Post.

Who are the bullies, Ms. Lewis? The city is not threatening to lock you out of the classrooms. The students are not threatening to boycott. Everyone else is willing to keep school open, and keep kids learning, while contract negotiations continue.

You are the ones walking away, interrupting the education process for thousands of underprivileged children who desperately need every minute of school they can get. You’re engaging in a massive shakedown to get what you want, and you don’t care who you hurt in the process.

That’s what bullies do.

The so-called educators of the CTU clearly have no dedication to their profession or their students. If they did, they would pressure their union leaders to negotiate for realistic goals that the school district may be able to meet without breaking the bank.

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The CTU is not so much a teachers union as it is a radical political organization that’s chomping at the bit to take to the streets and make as much trouble as possible. This organization has no more value to the city or society than the creepy malcontents in the Occupy movement.

But nobody can accuse CTU leaders of being stupid. They are announcing their plans to walk away just as the nation’s focus is shifting to the Democratic National Convention in Charlotte, N.C. The last thing the Obama campaign needs is an ugly strike in Chicago involving many of his biggest supporters.

You can bet the White House is pressuring Mayor Emanuel to do whatever he has to do to settle this thing, so it won’t distract from the convention and campaign.

If Emanuel caves, a dangerous message will be sent to teachers unions throughout the nation: Walk out on your students whenever you want, and make any sort of demands you want.  Eventually you will get your way, like a spoiled child making a scene in a grocery store.

When will we finally accept the obvious fact that union collective bargaining is a huge burden and unnecessary distraction that weakens and cheapens our education system. The focus of public education should be on the needs of students, period. But at the moment the students of Chicago are nothing more than pawns in a money war being waged by greedy adults.

This is not why we have public schools. But it may be yet another great reason to increase school choice and make private school vouchers available to students and families throughout the nation.

At least private school teachers don’t walk out on their students.