For the first time in decades, education policy has become a major issue in a Republican presidential campaign. Last month, former President Donald Trump, a frequent critic of “radical left indoctrination,” declared that he would cut funding to schools espousing “critical race theory,” “transgender insanity” or “any other inappropriate racial, sexual or political content.” Trump was trying to outbid Florida’s Republican Gov. Ron DeSantis, who has vowed to curb “woke indoctrination” and the use of tax dollars to teach kids “to hate our country or to hate each other.” South Dakota Gov. Kristi Noem, another potential Republican presidential contender, calls...