For 50 years Peggy Wallace Kennedy has lived in the shadow cast by her father, Alabama Gov. George C. Wallace, when he stood in a doorway and tried to stop two black students from integrating the University of Alabama.

That single episode in the American civil rights movement — his infamous “stand in the schoolhouse door” — attached an asterisk to her name, she says. It’s a permanent mark she can never erase, despite her own history as a moderate Democrat who gave early support to candidate Barack Obama for president in 2008.

“If you’re George Wallace’s daughter, people think the asterisk will always be there. ‘Oh, your father stood in the schoolhouse door,’” she said in a recent interview.

Kennedy was just 13 at the time. Her mother, Lurleen Wallace, had whisked her away to a lake fishing cabin with her three siblings that day, so they would be nowhere near the wrenching historic drama in which her father played a leading role....