The long-awaited Inspector General’s report on the FBI’s handling of the Hillary Clinton investigation makes for depressing reading for anyone who cares about American democracy. Self-government depends on public trust in its institutions, especially law enforcement. The IG’s 568-page report makes clear that the FBI under former director James Comey betrayed that public trust in a way not seen since J. Edgar Hoover.

We use the Hoover analogy advisedly, realizing that the problem in this case was not rampant illegal spying....