[1] Born in Chicago, Illinois, Kersten graduated from Marquette University College of Law, Milwaukee, Wisconsin, in 1925 and was admitted to the bar the same year.

He was a close friend of fellow freshman Congressman Richard Nixon.

He was an unsuccessful candidate for reelection in 1954, and failed in his bid for renomination in 1956, as of 2018 making him the last Republican to represent Milwaukee in the U.S. Congress.

In between these campaigns Kersten briefly served in the Eisenhower administration under Nelson Rockefeller as White House consultant on psychological warfare (1955–1956).

He then resumed his law practice, remaining active in anticommunist circles until his death on October 31, 1972, in Milwaukee, Wisconsin.