Article II, section 4, of the U.S. Constitution states: "The President, Vice President, and all civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other High Crimes and Misdemeanors."

The Framers of the Constitution deliberately used, but did not define, "high crimes and misdemeanors." Congress was left to decide the definition, and, thus, impeachment is a matter of political judgment. When the Constitution was being written, George Mason (1725-1792; see box in James Madison entry in volume 1) and James Madison (1751-1836; see entry in volume 1) argued that there were other "great and dangerous offenses" than treason and bribery, and Mason proposed adding "high crimes and misdemeanors." In eighteenth- century English language, a "misdemeanor" meant bad behavior (corruption, for example), and "high crimes" was similar to "great and dangerous offenses." Politicians, lawyers...