Hillary Clinton is good at imagining partisan plots, and to listen to her team, no less than several inspectors general, the intelligence community, and the entire Republican ecosphere are colluding to turn her home-brew email system into a fake scandal. To this conspiracy, she must now add the federal judiciary.

In recent weeks, not one, but two, esteemed federal judges have granted an outside group—Judicial Watch—the right to conduct discovery into the origins and handling of her private email system. It’s a reminder that...