Complex sentence: Graves served as an aide to U.S. Representative Billy Tauzin, formerly of Louisiana's 3rd congressional district for nine years, and as a legislative aide to the U.S. House Committee on Energy and Commerce, of which Tauzin served as chairmam.
Split into simpler sentences: Graves served as an aide for nine years to U.S. Representative Billy Tauzin, formerly of Louisiana's 3rd congressional district. He was also a legislative aide to the U.S. House Committee on Energy and Commerce, of which Tauzin served as chairmam.