 From 1976 to 1980, Coats worked for then-U.S. Representative Dan Quayle, a Republican from Indiana's 4th congressional district, as Quayle's district representative.When Quayle decided to challenge three-term Democratic incumbent Birch Bayh in the 1980 U.S. Senate election, Coats ran for and won Quayle's seat in the U.S. House.When Quayle resigned from the Senate after being elected Vice President of the United States in 1988, Coats was appointed to Quayle's former seat.