Well before Mr. Wofford pursued elective office, the self-described “New Deal Democrat” was known as a civil rights activist who participated in King’s 1965 march from Selma to Montgomery, Ala. Mr. Wofford was among the first whites to graduate from Howard University Law School.

Working on Mr. Kennedy’s 1960 presidential campaign, Mr. Wofford arranged a meeting between the candidate and Mr. King. And when Mr. King was arrested for participating in an Atlanta sit-in, Mr. Wofford advised that Mr. Kennedy call and offer sympathy to the reverend’s wife, Coretta Scott King.

That call has been credited with helping swing the election in Mr. Kennedy’s favor, after word of the gesture spread through black communities nationwide, helped by leaflets on blue paper the campaign quietly distributed at Mr. Wofford’s direction.