Teachers unions have been reliable Democratic allies since the 1970's. President Obama has nearly doubled the Department of Education budget and has pushed the teacher-supported Common Core standards nationwide.

But in a case of "what have you done for us lately," teachers unions are lashing out at President Obama and his Secretary of Education Arne Duncan. The largest teachers union, the NEA, has called for Duncan's resignation and other organizations are complaining bitterly about the president's "Race to the Top" program that holds teachers more responsible for the performance of studnets.

The Hill:

“Our members are frustrated and angry,” said NEA president Dennis Van Roekel. “Number one is the toxic testing. There is too much.”

An added spark came on June 10, when a California judge ruled the state’s teacher tenure laws are unconstitutional because they keep ineffective teachers in the classroom and deprive poor and minority students of their right to an equal education.

Teachers unions, which are strong defenders of tenure, expressed outrage when Duncan said the plaintiffs in the case were just some of millions of students disadvantaged by tenure laws. He called the decision “a mandate to fix these problems.”

With the teachers unions at loggerheads with the administration, Democrats are suddenly at risk of losing one of their most reliable allies and fundraising sources.

“[The California decision] caused some friction between the civil rights wing of the party and the more traditional labor wing of the party,” said Joe Williams, executive director of Democrats for Education Reform. 

Williams said Duncan and President Obama have diminished the unions’ historical dominance over the party’s platform for education. “They were the first elected Democrats at that high a level to connect directly with Democratic constituents rather than just the teachers unions,” he said.

Teachers unions traditionally have been generous donors to Democratic campaigns over the years, and that trend has carried into 2014. According to the Center for Responsive Politics, teachers unions have contributed about $9 million to candidates and $7 million in outside spending in the 2014 cycle, almost all for Democrats, and in line with 2010 levels.

But there’s no guarantee that the flow of campaign cash will continue.

Some of teachers unions’ fiercest sparring partners are now Democrats. Chicago Mayor Rahm Emanuel, Obama’s former chief of staff, clashed with unions during a teachers strike in 2012. Staunchly liberal New York City mayor Bill de Blasio has fought with Democratic governor Andrew Cuomo over charter schools, an education alternative that the Obama administration has encouraged.

Back in 2009, Obama’s choice of Duncan, a former Chicago superintendent, for secretary was seen as a compromise between a close ally of the teachers unions or a reformer such as former Washington superintendent Michelle Rhee.

But Duncan’s state competitions for funding have led to significant steps towards the reform vision, and away from the positions of teachers unions.

It isn't likely that teachers will begin supporting Republicans. But losing their enthusiasm for Democratic candidates is just as bad., Less cash, less volunteering and fewer votes cast as some teachers stay home on election day obviously favors the GOP.

Is it permanent? Probably not. Bill Clinton was the teacher's best friend and Hillary is likely to benefit from that relationship. And despite their anger, teachers still have plenty of clout in Washington. Look at the situation more as a temporary separation rather than a divoirce. Both sides need each other too much for any kind of permanent break to take place.