Forget Donald Trump’s plans to eliminate the U.S. Department of Education or allegations of fraud against Trump University: The real estate executive has already poisoned public schools, according to American Federation of Teachers President Randi Weingarten, by fostering a toxic environment that encourages bullying.

In a conference call with reporters on Thursday set up by the Democratic National Committee, Weingarten blasted the real estate executive for his “xenophobia” and his “promotion of violence.” And she said that it’s too late to turn back the clock on the negative effect he’s already had on public schools.

“My point is, he’s already done tremendous damage to education,” Weingarten said during a conference call with reporters. “He’s created an environment of scapegoating and demonizing. It is influencing children and it is influencing behavior in schools. It is making it much, much harder for us.”

Is there anything to back up Weingarten’s assertion? Last month, my colleague Evie Blad covered a survey conducted by the Southern Poverty Law Center showing that most teachers say their students—many of them Muslim or the children of immigrants—have expressed fears about their fate after the election. And 40 percent said they’re afraid to teacher their students about the election. However, that survey was not scientific.

There have also been reports of incidents like Donald Trump’s name being chanted by fans at a Wisconsin high school soccer game, along with “build that wall” and racial slurs. (Trump has pledged to halt illegal immigration from Mexico by building a wall along the southern border, and by making the Mexican government pay for it.) But in general, it’s hard to statistically identify exactly how Trump has or has not broadly influenced the climate of public schools.

Make no mistake, Weingarten and Democratic U.S. Rep. Mark Pocan of Wisconsin, who was also on the call, blasted Trump for his other positions on education too. Weingarten said she was not surprised that one of Trump’s high-profile surrogates is New Jersey Gov. Chris Christie, a Republican who has said teachers’ unions need a punch in the face.

“What we’re seeing is the presumptive nominee of the Republican Party be anti-teacher and anti-public education,” the AFT president said.

Donald Trump hasn’t taken many in-depth positions on K-12 during the campaign. But he has taken a few (relatively) clear positions on K-12. He wants to eliminate the Common Core State Standards—something the federal government cannot do. And as Weingarten noted, he’s said he wants to either severely cut or eliminate the Education Department—at the same time, he declared in March that education is one of the top three priorities for the federal government.

You might remember that both the AFT and the National Education Association moved pretty quickly to endorse former Secretary of State Hillary Clinton for the Democratic presidential nomination. That did not sit well with some members of the two unions, who thought that there ought to have been more consideration of Democratic candidate Sen. Bernie Sanders, I-Vt. So it’s not surprising that Weingarten in particular would come up swinging against Trump quickly and vigorously, now that he’s the presumptive nominee.