Richard K. Donahue, a confidant of the Kennedy political dynasty who served as president of the sportswear company Nike in the early 1990s and later saw his law license suspended after becoming embroiled in a tawdry courtroom saga, died Tuesday at his home in Lowell, Mass. He was 88.

A third-generation lawyer in Lowell, Donahue forged an enduring connection to the Kennedy political machine as a young man. He grew active in grass-roots organizing that spurred John F. Kennedy’s rise in the 1950s and early 1960s from congressman to senator to president.

In 1960, Donahue worked in primary battlegrounds such as West Virginia, a largely rural and Protestant state where Kennedy’s Catholic faith was seen as cause for concern in his bid for the White House. In response, he raised Kennedy’s World War II record aboard PT-109.

As Donahue later said, “I would get a call, ‘They’re murdering us here with the Catholic stuff.’ And I would say, ‘Hit ’em with the 109.’ West Virginia had the greatest percentage of gold-star mothers, really proud of what their sons had done in the service. That started to help.”

Kennedy’s triumph over Minnesota Sen. Hubert Humphrey in the primary was a vital hurdle in securing the Democratic nomination for president. Donahue was later described in journalist Theodore H. White’s “The Making of the President 1960” as “a coruscatingly brilliant young lawyer,” prompting Kennedy to quip, “50,000 votes the other way and we’d all be coruscatingly stupid.”

Donahue later held the title of assistant to the president.