My view was that every executive officer, and above all every executive officer in high position, was a steward of the people bound actively and affirmatively to do all he could for the people, and not to content himself with the negative merit of keeping his talents undamaged in a napkin. I declined to adopt the view that what was imperatively necessary for the Nation could not be done by the President unless he could find some specific authorization to do it. My belief was that it was not only his right but his duty to do anything that the needs of the Nation demanded unless such action was forbidden by the Constitution or by the laws. Under this interpretation of executive power I did and caused to be done many things not previously done by the President and the heads of the departments. I did not usurp power, but I did greatly broaden the use of executive power. In other words, I acted for the public welfare, I acted for the common well-being of all our people, whenever and in whatever manner was necessary, unless prevented by direct constitutional or legislative prohibition.

Theodore Roosevelt (1858-1919) American politician, statesman, conservationist, writer, US President (1901-1909)
Theodore Roosevelt, An Autobiography, ch. 10 (1926)