Al Franken's 2008 United States Senate election opponent had previously been a member of which political party before becoming a Republican?
United States Senate election in Minnesota, 2008: The 2008 United States Senate election in Minnesota took place on November 4, 2008. United States Senate election in Minnesota, 2008:  After a legal battle lasting over eight months, Al Franken from the Democratic-Farmer-Labor Party (DFL) defeated Republican incumbent Norm Coleman in one of the closest elections in the history of the Senate. Norm Coleman: Norman Bertram Coleman Jr., (born August 17, 1949) is an American lobbyist, lawyer and politician. Norm Coleman:  Previously a member of the Democratic–Farmer–Labor Party (DFL), Coleman became a Republican in 1996.
Democratic-Farmer-Labor Party (DFL)