After receiving the nomination of his one-party state in 1936 and being assured of a seat in the Senate beyond Franklin Roosevelt's second term, Jimmy Byrnes indeed began to "jump the traces," in Harold Ickes' prophetic image of a nervous, headstrong horse escaping its restraints and going its own way. Before his return to the Senate in 1937, few southern elected officials had been publicly more in support of a liberal New Deal nationalism than had Jimmy Byrnes. For example, a week after the U. S. Supreme Court on May 27, 1935, declared the NIRA unconstitutional, Byrnes went back to South Carolina to make a speech criticizing the Court's decision. Probably as a favor to Franklin Roosevelt, to allow his administration to test public reaction to the idea, Byrnes proposed that the Constitution be amended so as to make legal the regulation of business by the NRA. Roosevelt eventually had other plans for the Supreme Court, and nothing more came of Byrnes' proposal, but it was extraordinary for Byrnes even to have suggested such a radical alteration of the Constitution in a state as conservative as South Carolina.
The exceptional loyalty of Senator Jimmy Byrnes to a New Deal economic nationalism under FDR during his first term in office can be matched