Democratic presidential candidates ranted against charter schools Friday while some hyped public education plans that would cost trillions of dollars.

The National Education Association, the largest union in the United States, was hosting an education forum in Houston, the Washington Examiner reported.

New York Mayor Bill de Blasio made it clear that the he no time at all for schooling outside of the public domain. “I am sick and tired of these efforts to privatize a precious thing we need, public education,” he told the group, adding, “I know we’re not supposed to be saying ‘hate,’ our teachers taught us not to. I hate the privatizers, and I want to stop them.” In addition to hating private schools, de Blasio promised to defund them.

Independent Vermont Sen. Bernie Sanders promised an end to all federal funding for for-profit schools while suspending any further funding for all charter schools pending the results of a federal commission that would audit their activities.

One-time Texas Rep. Beto O’Rourke allowed “a place for public nonprofit charter schools” but promised “not a single dime” for private charter schools and voucher programs.

The candidates also jockeyed for position by promising to outspend each other on public education. Massachusetts Sen. Elizabeth Warren reminded union members of her plan to federally fund early childhood education programs by taxing millionaires and billionaires. The Warren education plan could easily total $700 billion over the next decade, according to one cost estimate.

Sanders reminded everyone of his announcement that he is prepared to liquidate $1.6 trillion in student loan debt combined with free tuition for all in the future through new taxes. (RELATED: Report: Sanders Will Introduce Bill That Will Make $1.6 Trillion In Student Loan Debt Disappear)

“I have been criticized for this proposal. I’m criticized for every proposal because I try to stand up for working families in this country and not the billionaire class,” Sanders said. “But on this proposal, if we can bail out the crooks on wall street to the tune of billions of dollars, we surely can cancel student debt in America.”

The candidates then turned to Trump Education Secretary Betsy DeVos, criticizing her for not having sufficient time in the classroom. Most promised to replace DeVos with an experienced teacher, while Warren suggested that the current secretary “need not apply” if the senator becomes the next president. (RELATED: Warren Wants To Give Billions To Historically Black Colleges. They Typically Have Among The Lowest Loan Repayments)

Former Vice President Joe Biden seemed content to joke that he would not appoint his wife Jill Biden, who has taught high school, as the next education secretary although “she would be a good one.”

Julián Castro, former President Barack Obama’s housing secretary, chose to take the discussion in an entirely different direction, commenting on the school busing issue that California Sen. Kamala Harris so successfully used against Biden in the second Democratic debate last week.

“I would invest in tools like voluntary busing so that within school districts, folks are able to go to different schools,” Castro said.

The National Education Association has a membership of other three million and remains a powerful force in American politics — reserving all of that influence for the Democratic Party. The union supported former Secretary of State Hillary Clinton in the 2016 presidential election — enraging the more progressive followers of her opponent, Sanders.