The great accession to presidential power in recent decades has been accompanied by the breakdown dealt with earlier of the two great structural principles of the American Constitutional System, the doctrine of Dual Federalism and the doctrine of the Separation of Powers. The first exponent of "the New Presidency", as some termed it, was Theodore Roosevelt, who tells us in his _Autobiography_ that the principle which governed him in his exercise of the presidential office was that he had not only a right but a duty "to do anything that the needs of the Nation demanded unless such action was forbidden by the Constitution or by the laws."[53] In his book, _Our Chief Magistrate and his Powers_, Ex-President Taft warmly protested against the notion that the President has any constitutional warrant to attempt the role of a "Universal Providence."[54] A decade earlier his destined successor, Woodrow Wilson, had avowed the opinion that "the President is at liberty, both in law and conscience, to be as big a man as he can".[55] But it is the second Roosevelt who beyond all twentieth-century Presidents succeeded in affixing the stamp both of personality and of crisis upon the Presidency as it exists at this moment. In the solution of the problems of an economic crisis, "a crisis greater than war", he claimed for the National Government in general, and for the President in particular, powers which they had hitherto exercised only on the justification of war. Then when the greatest crisis in the history of our international relations arose, he imparted to the President's diplomatic powers new extension, now without consulting Congress, now with Congress's approval; and when at last we entered World War II, he endowed the precedents of both the War between the States and of World War I with unprecedented scope.[56]