During President Roosevelt's first term in office (1932-1936) the Supreme Court ruled several landmark New Deal measures unconstitutional; a handful of these decisions were by 5-4 margins. It all changed in 1937, when swing Justice Owen Roberts voted to affirm a minimum wage statute in West Coast Hotel Co. v. Parrish; a year earlier he had voted against minimum wage legislation in a similar case. This "switch in time that saved nine" has no established consensus that explains its occurrence. Some have posited that President Roosevelt's "court packing" legislation forced Roberts's hand, while other have argued that public opinion caused Roberts's swing in jurisprudence. This paper approaches the question in two realms. First, the specific jurisprudence of Justice Roberts on economic and labor rights issues is examined, producing an original dataset that provides a clear indication of where Roberts stood on these matters from 1931-1937. Using this dataset, which denotes an undeniable conservtive shift pre-Parrish (1934-1936), and a marked liberal shift post the 1936 election, this paper constructs a compelling argument that Justice Roberts's varying jurisprudence was not guided as much by public opinion, or differing legal arguments, but rather by a desire to run against President Roosevelt in the 1936 election. It is an explanation, supported by a plethora of original evidence, that most comprehensively explains Justice Roberts's confounding jurisprudence from 1933-1937.