Education Secretary Betsy DeVos has made clear her intention to correct one of the Obama administration’s worst excesses—its unjust rules governing sexual misconduct on college campuses. In a forceful speech Thursday at Virginia’s George Mason University, Mrs. DeVos said that “one rape is one too many”—but also that “one person denied due process is one too many.” Mrs. DeVos declared that “every student accused of sexual misconduct must know that guilt is not predetermined.”

This might seem like an obvious affirmation of fundamental...