Democratic presidential candidate Hillary Clinton won the endorsement of the 1.6 million-member American Federation of Teachers this weekend, which was not a surprise. The union endorsed her over Barack Obama in 2008, and AFT President Randi Weingarten is a longtime Clinton ally.

In a statement on the AFT website, Weingarten said, "Hillary Clinton, a product of public schools herself, believes in the promise of public education. From early childhood learning through higher education, she sees how that promise can create real opportunity for kids, building a much-needed bridge to the middle class. Hillary understands that to reclaim the promise of public education, policymakers need to work with educators and their unions. She's ready to work with us to confront the issues facing children and their families today, including poverty, wage stagnation, income inequality and lack of opportunity. Hillary is the leader we need to help us reclaim the promise of public education and, indeed, of America."

The AFT statement included a comment from Clinton: “I know from my own family that teachers have the power to change lives. We need to make sure every child has access to a quality public education and teachers with the tools to help them succeed. Our country’s future depends on the education we give all our children — and giving them the best means working with the teachers and school personnel who help shape their futures each day.”

The endorsement is already causing a backlash, including a petition on Change.org urging the AFT to withdraw its Clinton endorsement. Some petition supporters prefer Vermont Sen. Bernie Sanders to Clinton.

The petition, which drew 2,500 signatures in the first 24 hours, states:

Today, the American Federation of Teachers officially endorsed Hillary Clinton for the Democratic Presidential Nomination. There are several reasons why this is unbelievable, but here are the top three:

1. Hillary Clinton is on record for supporting the expanded use of charter schools, which directly and negatively impacts public education.

2. Clinton also is in favor of tying teacher pay to student performance on standardized tests. These tests are proven to be biased and an inaccurate measure of student achievement.

3. Other candidates are much more teacher friendly. For example, Bernie Sanders is a product of public education and wants to help teachers teach in a holistic way, not just teach toward a test.

Among the comments from educators signing the petition:

•We need someone who is committed to rebuilding public education to its former glory. This will not happen if teachers, parents and communities do not unite and stand against the corporatization of public schools. The support that Hillary receives from Wall Street, and gives them in return, and her misguided support of charter schools clearly shows whose interests she is working for. End Clinton Cronyism and support the candidate who has always had the interest of the 99% at heart, Bernie Sanders.

•We must save public education and completely end the charter/voucher school idea!