 On January 29 , 2007 , Franken announced his departure from Air America Radio , and on the day of his final show , February 14 , Franken formally announced his candidacy for the United States Senate from Minnesota in 2008 . Challenging him for the Democratic – Farmer – Labor Party endorsement was Jack Nelson @-@ Pallmeyer , a professor , author , and activist . Other candidates were trial lawyer Mike Ciresi and attorney and human rights activist Jim Cohen , who had dropped out of the race earlier . Franken won the nomination with 65 % of the vote . 
