We are living in an era when the very idea of public education is under attack, as are teachers' unions and the teaching profession. Let's be clear: these attacks and the power amassed behind them are unprecedented in American history. Sure, there have always been critics of public schools, of teachers, and of unions. But never before has there been a serious and sustained effort to defund public education, to turn public money over to unaccountable private hands, and to weaken and eliminate collective bargaining wherever it still exists. And this effort is not only well-coordinated but funded by billionaires who have grown wealthy in a free market and can't see any need for regulation or unions or public schools.

In the past, Democratic administrations and Democratic members of Congress could be counted on to support public education and to fight privatization. In the past, Democrats supported unions, which they saw as a dependable and significant part of their base.

This is no longer the case. Congress is about to pass legislation to expand funding of charter schools, despite the fact that they get no better results than public schools and despite the scandalous misuse of public funds by charter operators in many states.

The Obama administration strongly supports privatization via charters; one condition of Race to the Top was that states had to increase the number of charters. The administration is no friend of teachers or of teacher unions. Secretary Duncan applauded the lamentable Vergara decision, as he has applauded privatization and evaluating teachers by the test scores of their students. There are never too many tests for this administration. Although the president recently talked about the importance of unions, he has done nothing to support them when they are under attack. Former members of his administration are leading the war against teachers and their unions.

Think Rahm Emanuel, who apparently wants to be known as the mayor who privatized Chicago and broke the teachers' union. Or think Robert Gibbs, the former White House press secretary who is now leading the public relations campaign against teachers' due process rights.

The National Education Association is meeting now in Denver at its annual conference. The American Federation of Teachers holds its annual convention in Los Angeles in another week or so. Both must take seriously the threat to the survival of public education: not only privatization but austerity and over-testing. These are not different threats. They are connected. Austerity and over-testing set public schools up to fail. They are precursors to privatization. They are intended to make public schools weak and to destroy public confidence in democratically controlled schools. What is needed at this hour is a strong, militant response to these attacks on teachers, public schools, and -- where they exist -- unions.

For sure, unions have their faults. But they are the only collective voice that teachers have. Now is the time to use that voice. The battle for the future of public education is not over.

Supporters of public education must rally and stand together and elect a president in 2016 who supports public schools. This is a time to get informed, to organize, to strategize, and to mobilize. If you are not angry, you have not been paying attention.