The speech that Attorney General Merrick Garland delivered Thursday at the Justice Department must have been intended to echo throughout the land. After thanking the DOJ’s 115,000 staff for their work to prosecute heinous crimes and hold polluters accountable, he turned to the topic, implicitly, of Donald Trump. Mr. Garland lauded the ideal of equal and impartial justice, while saying he’s seen in his tenure how DOJ employees have upheld it. “Our norms,” the AG said, “are a promise that we will not allow this department to be used as a political weapon. And our norms are a promise that...