PITTSBURGH – Rhonda “Randi” Weingarten, head of the nation’s second-largest teachers union, has a reputation for waxing poetic about how public education can improve only if teachers, school leaders and reformers “collaborate.”

Case in point is a 2011 op-ed in which Weingarten wrote that “collaborative school reform is a story worth telling, and it’s our best hope for improving America’s schools.”

We always knew Weingarten’s message of “collaboration” was only as a smokescreen to make her radical union appear reasonable and to confuse Americans who are on the fence about whether teacher unions are a force for good or ill in our nation’s public schools.

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Now we can prove it.

KDKA-TV reports the Pittsburgh school district is in jeopardy of losing the remainder of a $40 million grant it received from the Bill and Melinda Gates Foundation in 2010 because the Pittsburgh Federation of Teachers – a local affiliate of Weingarten’s AFT – won’t agree to a rigorous, new evaluation system.

“Under the grant, the union and the district were to develop a criteria to evaluate teacher performance with the idea of rewarding superior educators and retraining those who could not make the grade,” KDKA-TV reports.

District and the PFT leaders “had an agreement on the evaluations, but they broke down over implementation,” KDKA-TV reports. The union was unhappy with the evaluation’s “cut” score, the minimum evaluation score that teachers must reach in order to avoid certain interventions, such as retraining.

PFT President Nina Esposito-Vigitis complained that “good teachers” would lose their jobs under the plan.

According to a KDKA-TV analysis, 85 percent of Pittsburgh teachers would make the grade under the proposed evaluation system, and 15 percent would require some sort of remediation.

In union-land, virtually all teachers are “good,” and only a tiny handful of educators deserve to be shown the door. That’s why so many public schools have become centers of mediocrity and American students are falling behind their peers in other nations.

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Pittsburgh schools Superintendent Linda Lane said she has tried to address the union’s concerns by lowering the minimum score twice.

But Superintendent Lane isn’t just dealing with the local teachers union.

KDKA-TV reports that Weingarten’s AFT “has put people and resources in Pittsburgh” to strike down this evaluation plan. The news site adds that Weingarten’s AFT and the local PFT “have hit Lane … with a flurry of ‘right to know’ requests – her daily schedules and correspondence – and Lane says the fight has become personal.”

In an open letter to Superintendent Lane, Weingarten and another union bigwig blast her for pushing “punitive cut-scores” that are “10 times higher than the national average and completely out of line with standards in the rest of the state.”

“The future of Pittsburgh schools is a matter of great importance locally, statewide and nationally, and we are going to stand with (PFT) President (Nina) Esposito-Visgitis and Pittsburgh’s educators in this crucial fight to improve schools and help students learn.”

For those unfamiliar with union-speak, here’s a translation: Weingarten and company are admitting that this is a “crucial fight” because if Pittsburgh schools succeed in holding ineffective teachers accountable, other schools districts will follow suit.

And that’s something the AFT won’t allow to happen.

Despite all of Weingarten’s happy-talk about wanting “collaborative” reform, the AFT – like all labor unions – exists to represent the needs of its dues-paying members – especially the weakest and worst-performing ones.

The unions’ stubborn refusal to make the evaluation plan work has Gates Foundation officials threatening to pull the plug on the grant. Pittsburgh Mayor Bill Peduto recently traveled to Seattle to ask foundation officials for nine more months to try and hammer out an agreement with the union and school leaders, the news site reports.

One observer said losing the grant would be “devastating” to students and the entire Pittsburgh community.

It’s possible that the loss of the Gates grant could lead to program cuts for students and higher property taxes for struggling Pittsburgh families.

But Weingarten and her fellow unionists are okay with that because they need to win this fight, whatever the cost.

When it comes to “collaboration,” Weingarten may talk a good game, but in reality, she’s a total hypocrite.