Fewer than three of 10 Americans trust government to do the right thing always or most of the time, Gallup reports, and the years since 2007 are “the longest period of low trust in government in more than 50 years.” The details emerging about the multiple investigations into Hillary Clinton explain a lot about this ebbing public confidence in institutions such as the Justice Department and Federal Bureau of Investigation.

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Start with Attorney General Loretta Lynch. A cavalcade of former Justice heavyweights are now assailing...