… is from page 82 of my great teacher Leland Yeager’s, and David Tuerck’s, excellent 1966 book, Trade Policy and the Price System  (emphasis added):
No reforms of the political mechanism could make morality on the part of the voter and politician quite unnecessary. To the constitutional theorist, the traditional appeals to the consciences of voters and politicians should not sound like nonsense, for constitutionalism and concepts of political morality interpenetrate each other. The written words of a constitution do not enforce themselves. People must be generally willing to abide by its letter and spirit both, instead of regarding it as something to be twisted or ignored as suits their immediate purpose. A tradition of political morality is necessary to keep a written constitution meaningful.