He is still the longest - serving congressman in South Carolina 's history , and only Strom Thurmond represented the state longer at the federal level .
McMillan was defeated in the 1972 Democratic primary by a considerably more liberal Democrat , State Representative John Jenrette .
McMillan is still the longest - serving McMillan in South Carolina 's history , and only Strom Thurmond represented the state longer at the federal level .
McMillan was defeated in the 1972 Democratic primary by a considerably more liberal Democrat , State Representative John Jenrette .