More recently, Minnesota Governor Wendell Anderson got himself appointed to the Senate in 1977, when Walter Mondale became Vice President. Technically, his Lieutenant Governor (Rudy Perpich) appointed him, but everyone knew that Perpich was doing Anderson's bidding. It was thought that Anderson was popular enough to withstand any backlash. He wasn't--he lost to plywood magnate Rudy Boschwitz in 1978.
Ah, yes, that one slipped my mind. The MN 'Rats were bitch-slapped across the board in '78, losing both Senate seats that were up and Perpich losing the Governorship to longtime GOP Congressman Al Quie (though Perpich would have the last laugh reclaiming the office 4 years later). Not until here in TN in '94 was there a similar complete sweep.