The constitutional provision is that impeachment may be had for "treason, bribery, or other high crimes or misdemeanors."

The terms "treason" and "bribery" require no definition. Treason is, indeed, defined in the Constitution itself, and the offense of bribery is sufficiently definite and well known. To the term "high crimes and misdemeanors," practice has given a broad meaning that brings within its connotation offenses not penal by federal statute. Professor Thomas, in the article to which reference has been made, points out that in the first four impeachment trials not a single charge rested upon a statute, and the same was true of some at least of the articles in most of the trials.

4 Cf. article by Prof. Thomas in American Political Science Review.

It would also seem to be established that the offense charged need not be one committed in the discharge of official duties.5

In short, then, it may be said that impeachment will lie whenever a majority of the House of Representatives are for any reason led to hold that the incumbent of a civil office under the United States is morally unfit for and should no longer remain in his position of public trust.