The culture wars are blazing again. This time, the subject is high school history. The College Board, the private company that administers the Advanced Placement exam, released a new framework for AP history classes. Conservatives reacted with fury.

A Republican National Committee resolution savaged the curricular recommendations as a “radically revisionist slant on history.” Fox News personality and possible 2016 presidential candidate Dr. Ben Carson called them so tilted to the left that “most people, when they finish that course, they’d be ready to sign up for ISIS.”

And in Jefferson County, Colorado—one of the fifty biggest school districts in the United States—the controversy has brought the teaching of high school history to a stand-still: After a new conservative majority on the school board ordered a review of the allegedly offensive materials, students walked out of class in droves, and dozens of teachers called in sick in protest. As of this writing, matters there remain in a tense standoff.

So what’s behind this impassioned outpouring? In part, the controversy evinces the right-wing antipathy to federal dictates that undercut local control, especially local control of education. Ronald Reagan, for example, in his campaign for the 1976 Republican presidential nomination, excoriated the National Education Association for working toward what he called a “national education system”—like the one imposed, a long time ago, in Germany: “They changed their academic system to suit the rule of the dictator. … When [he] said burn the books, they burned the books.”

In this spirit, because the College Board noted that the new AP framework is meant to harmonize with the Obama Administration’s national “Common Core” standards, the Republican-controlled legislature in Texas considered jettisoning AP history courses altogether, consistent with a 2013 law that prohibits the teaching of materials from the Common Core. There is also is the familiar right-wing criticism of history that allegedly slights the Great White Males in favor of emphasizing the history of women and minorities.

But there is an even more crucial factor at play here: American conservatism’s historic addiction to the power of positive thinking...