Attorney General Merrick Garland is not going to save democracy. Nor is the attorney general of New York, Letitia James; the Manhattan district attorney, Alvin Bragg; nor the Fulton County district attorney, Fani Willis. As the apparent collapse of the New York district attorney’s investigation makes clear, criminal cases are hard to make. Donald Trump, despite his many seemingly criminal acts, is unlikely to ever spend a day in jail. Observers of the Trump malignancy have an unfortunate habit of wish casting—believing that their most optimistic fantasies will become reality. They did this with the Mueller investigation—remember “It’s Mueller Time”?—and...