Roosevelt didn't have an easy time with his agenda; he had to first emasculate the U.S. Supreme Court. Higgs points out that federal courts had respect for the Constitution as late as the 1930s. They issued some 1,600 injunctions to restrain officials from carrying out acts of Congress.
A more fundamental question is: Should Washington be guided by the Constitution? In explaining the Constitution, James Madison, the acknowledged father of the Constitution, wrote in Federalist Paper 45: "The powers delegated by the proposed Constitution to the federal government are few and defined. Those which are to remain in the State governments are numerous and indefinite. The former will be exercised principally on external objects, as war, peace, negotiation, and foreign commerce." Has the Constitution been amended to permit Congress to tax, spend and regulate as it pleases or have Americans said, "To hell with the Constitution"?