His father, Harley Staggers, Sr., was a Democratic Congressman from West Virginia from 1949 until 1981, when he declined to run for a seventeenth term. After Harley, Sr.'s Republican successor, Cleve Benedict, gave up his seat after one term to run against Senator Robert Byrd, Harley, Jr. ran for the seat and won. He was reelected four more times.
Harley, Jr. lost his seat after West Virginia lost one congressional seat following the 1990 Census. Most of his former 2nd District's territory was merged with the Charleston-based 3rd District of fellow Democrat Bob Wise to form a new . However, his home in Mineral County was drawn into the , represented by fellow Democrat Alan Mollohan. Harley, Jr. opted to challenge Mollohan in the Democratic primary, and was soundly defeated.
Staggers practices law in Keyser, West Virginia with his brother, Daniel C. Staggers.