Kean became a candidate for the U.S. House of Representatives in 1938, running in New Jersey's 12th congressional district, which was based in Essex County. Republicans had held the seat from 1914 until 1936, when Democrat Frank W. Towey, Jr. won it on the coattails of President Franklin Roosevelt's re-election. The seat was viewed as likely to return Republican, and six Republicans sought the nomination in the September 20 primary. Kean won by a narrow 713 vote margin, 13,923 to 13,210 over Montclair Town Commissioner Dallas S. Townsend. Kean was endorsed by the "Clean Government" faction of the Essex GOP, while Townsend had the backing of the "Suburban Republican" faction. In the General Election, Kean defeated Towey by 12,118 votes, 48,854 (55%) to 36,736 (41%).