Sen. Carl Levin (D-MI) said he will not seek re-election in 2014, the Detroit News reports.
Levin, chairman of the powerful Senate Armed Services Committee, has been in the Senate since 1979. He said it was an "extremely difficult" decision.
Detroit Free Press: "Levin's departure could come at a bad time for Democrats as they look for a strong candidate to take on Republican Gov. Rick Snyder but Michigan has had few Republicans succeed at winning U.S. Senate seats in recent elections - the most recent being Spencer Abraham in 1994, who served one term before being beaten by the state's junior senator, Democrat Debbie Stabenow."