Great Britain has never had a written constitution. And Parliament has never sat down to write an impeachment statute with a neat definition of the behavior that could get a royal minister impeached. Rather, Parliament has carefully kept impeachment open-ended, recognizing that one never knew in advance what form the royal urge to autocracy might take or what sort of devilry corrupt or ambitious officials might be up to. Over the centuries, Parliament impeached a good many people for a wide variety of misconduct. When it did, the articles of impeachment tended to describe the defendant’s behavior as “high crimes and misdemeanors,” a usage that dates back to 1386. Critically, a great deal of the misconduct Parliament deemed impeachable wasn’t criminal at all, at least in the sense of violating any preexisting criminal statute or constituting any judge-created common-law crime.
I could provide examples in eye-glazing antiquarian detail. Suffice it to say that Parliament has impeached high officials for military mismanagement (Lord Latimer, 1376; the Earl of Suffolk, 1386; the Duke of Buckingham, 1626; and the Earl of Strafford, 1640), neglect of duty or sheer ineptitude (Attorney General Henry Yelverton; Lord Treasurer Middlesex, 1624; the Earl of Clarendon, 1667; Lord Danby, 1678; and Edward Seymour, treasurer of the Navy, 1680), and giving the sovereign bad advice, especially about foreign affairs (William de la Pole, 1450; Lords Oxford, Bolingbroke, and Strafford, 1715).
Parliament has also impeached a good many officers for abuse of power, sometimes criminal, but oftentimes not. When the Constitutional Convention convened in Philadelphia in the summer of 1787, the English-speaking world was riveted by the commencement of impeachment proceedings against Warren Hastings, governor general of Bengal, on just such grounds. Few if any of the charges against Hastings were indictable crimes, but that was immaterial to Edmund Burke, the principal parliamentary prosecutor of Hastings. He said the charges “were crimes, not against forms, but against those eternal laws of justice, which are our rule and our birthright: his offenses are not in formal, technical language, but in reality, in substance and effect, High Crimes and High Misdemeanors.”