Education Secretary Arne Duncan’s relations with teachers unions just got more difficult.

Delegates of the National Education Association, the nation’s largest teachers union, voted at their annual convention to call on Duncan to resign after similar efforts had failed in previous years. And the NEA is about to get a new president, Lily Eskelsen García, who is known for her tough talk and determination to fight back against corporate school reformers. She told the delegates:

“People who don’t know what they’re talking about are talking about increasing the use of commercial standardized tests in high-stakes decisions about students and about educators … when all the evidence that can be gathered shows that it is corrupting what it means to teach and what it means to learn….
We know what is at stake, and it is why we are who we are. It is why we are fearless and why we will not be silent when people who, for their own profit and political posture, subvert words like ‘reform’ or ‘accountability.'”

The delegates voted on a surprise agenda item that said the “department’s failed education agenda focused on more high-stakes testing, grading and pitting public school students against each other based on test scores, and for continuing to promote policies and decisions that undermine public schools and colleges, the teaching education professionals, and education unions,” according to the Associated Press.

Similar measures have failed at NEA conventions in recent years as the union has attempted to walk a line between staking out its own positions on school reform and trying not to seem as it were being reflexively oppositional at a time when President Obama’s education agenda had bipartisan support and when union leaders did not see any political alternative to the Democratic administration. NEA President Dennis Van Roekel had said for years that while the union and the administration could disagree on specific reforms, they both believed in public education. The NEA endorsed Obama in both of his presidential campaigns.

Things are different today. It is no surprise that such a vote succeeded this year, when the activist Eskelsen García is set to take command of the union and shortly after the verdict in a trial known as Vergara vs. California, in which a judge tossed out California statutes that provided job protections to teachers, and Duncan issued a statement that in some measure supported the decision. (The judge stayed his decision until an appeal can be heard.)

Eskelsen García, who once served school lunches to students and was a kindergarten aide before becoming an elementary school teacher in Utah, will ascend on Sept. 1 from her position as NEA vice president to president, taking over from Van Roekel.

According to the Associated Press, Duncan reacted to the NEA’s vote by saying that his department has been on good terms with the union. And he said:

“I always try to stay out of local union politics. I think most teachers do, too.”

Whether most teachers do or don’t try to stay out of local union politics isn’t the point. This vote isn’t a local union political action; it’s national. And even if most teachers were generally politics-averse, it wouldn’t mean they don’t support positions taken by their union.

Duncan can try to downplay the vote, but it signals the advent of a more activist NEA. And Randi Weingarten, president of the American Federation of Teachers, the second largest teachers union in the country, has for some time been taking on the Obama administration and Duncan over their education reform policies that revolve around standardized test-based accountability and that are seen by many teachers as assaults on their profession. Duncan’s support for evaluating teachers by student standardized test scores — a method assessment experts warn against — has rankled teachers, as has his support for Teach For America and for allowing TFA recruits to be seen as “highly effective teachers” after only five weeks of summer training.

Nobody should expect Duncan to take the NEA’s advice and resign, as he continues to have the support of the president and keeps rolling out initiatives in an effort to keep momentum up for his reform agenda. But the NEA vote is a new sign of growing disenchantment with Duncan’s policies from the unions and well beyond them, as parents, principals, superintendents and others protest the Duncan agenda. As a taste of what he can expect from Eskelsen García, she told the delegates:

“For us, one thing is clear, before anything is going to get better: It’s the testing, stupid. Better yet, it’s the stupid testing.”