In 1978, all three key statewide races were up for election -- the Governorship, and both Senate Seats (the other Senate seat belonged to Hubert Humphrey, who died in 1978). But, there was a particular oddity to the three races -- all three had incumbents who were never elected to the office in the first place. This became a well played issue by the Republicans -- a billboard put up across the state read, "The DFL is going to face something scary -- an election".
When Walter Mondale ascended to the Vice Presidency in 1976, sitting Governor Wendell Anderson appointed himself to the open seat. This act did not sit well with the electorate. Plywood magnate Rudy Boschwitz campaigned as a liberal Republican and spent freely of his own money, but all that seemed to really matter was that he was neither a DFLer or Wendell Anderson in an election cycle where both were rejected by the voters. The end result was not even close -- the challenger Boschwitz won in a 16 point landslide as all three statewide offices switched into Republican hands.