US Secretary of War Henry Stimson hired McCloy as a consultant in September 1940, who became immersed in war planning even though he was a Republican Party supporter and opposed Franklin Roosevelt for the upcoming November 1940 presidential election. Stimson was particularly interested in McCloy due to McCloy's extensive experience with German sabotage in the Black Tom case. Stimson knew that the Germans would once again try to sabotage American infrastructure if a war against the United States were to break out.