“I don’t think she is this devil enemy of public education that she’s been painted to be,” says Michael Horn, senior strategist at Guild Education and the co-founder of the Clayton Christensen Institute for Disruptive Innovation. “But there is a real backlash. And I think that is a real worry and a real risk. Education was a very bipartisan issue some 20 years ago.” Cracks in that bipartisan truce between parties started to show during the Obama years, Mr. Horn says. And then, he says, it “slid off the cliff over the past four years.”

Charter schools, which were pushed by Democrats a decade ago, have become a toxic issue for many in the party. So has the issue of whether and how schools should reopen during the coronavirus pandemic.