He graduated from the University of Michigan at Ann Arbor in 1905, and subsequently served as secretary to Chief Justice Melville W. Fuller of the Supreme Court of the United States from 1905 to 1907.

During his term, Day opposed U.S. involvement in World War II, claiming it would entail "national suicide" and "economic slavery".

Day published a book, We Must Save the Republic, through Flanders Hall, a small company with ties to registered Nazi agents.

In an investigation of Viereck's links to Congress, Day was named as one of four federal politicians who had knowingly collaborated.

[citation needed] This article incorporates public domain material from the Biographical Directory of the United States Congress