Nelson was the former Mayor of St. Paul (1922-1926) and Republican nominee for U.S. Senate in 1928. He would later win a special election to the U.S. Senate in 1942.
Ellsworth was an attorney from Minneapolis, former Watonwan County prosecuting attorney (1905-1909), former U.S. Representative (CD 02, 1915-1921), and candidate for Governor in 1920, 1922, 1924, and 1932. He also was a candidate for Lieutenant Governor in 1934, 1940, and 1942.
Knutson was a farmer and attorney from Benson, former state Representative (HD 56, 1907-1909, 1911-1913; HD 25, 1915-1919), candidate for Railroad and Warehouse Commissioner in 1928 and 1942, and candidate for an at-large U.S. House seat in 1932.
Sweitzer was a contractor from St. Paul and sitting state Representative (HD 42, 1921-1937).
Modeen was an attorney from Minneapolis, candidate for an at-large U.S. House seat in 1932, candidate for the SD 29 special election in December 1932, and candidate for Associate Justice of the Supreme Court in 1934.