WASHINGTON — Joseph D. Duffey, a coal miner’s son who led two large universities and two federal agencies and whose enduring luster in the Democratic Party stemmed from his unsuccessful but high-profile Senate bid in 1970, an antiwar campaign that drew support from Hollywood star Paul Newman and was staffed by a young Bill Clinton, died Feb. 25 in Washington. He was 88.

His death, at a retirement community, was confirmed by his son Michael, who did not provide a specific cause.

A former United Church of Christ minister with a doctorate in the history of theology, Dr. Duffey chaired the National Endowment for the Humanities under President Carter and led the University of Massachusetts Amherst from 1982 to 1991. After a brief stint as president of American University, he served six years as the last director of the US Information Agency.

With his second wife, Anne Wexler, who chaired his Senate campaign and became one of the first women to own a lobbying firm, Dr. Duffey was for years half of an influential Washington power couple.

But he was perhaps best known for his political activism in the 1960s and early ‘70s, when he helped organize Freedom Rides to the South and immersed himself in liberal politics, distressed by what he called the ‘‘carnage in Vietnam.’’ He was a leader of Senator Eugene McCarthy’s, Democrat of Minnesota, antiwar presidential campaign in Connecticut, where he was teaching at the Hartford Seminary Foundation, and he succeeded economist John Kenneth Galbraith as head of Americans for Democratic Action.

In 1970, at age 38, he won the Democratic Senate primary in Connecticut, beating a wealthy Stamford businessman favored by the state’s party machine. Although Dr. Duffey lost in the general election to Lowell Weicker, a Republican congressman, his campaign made him one of the nation’s most prominent antiwar activists and a hero to young political idealists, including a Yale law student named Bill Clinton.

‘‘In the fall of 1970, I missed about half of my law school classes trying to help get Joe Duffey elected to the Senate,’’ Clinton said in a statement. ‘‘There were so many of us who were drawn to his deep commitment to peace, economic fairness, and civil rights. Joe lost the election, but he left us all proud, wiser in the ways of politics, and richer in lifelong friends, including Joe himself.’’

Dr. Duffey’s campaign was chaired by Wexler and included a host of ambitious political operatives, including Tony Podesta, who managed the campaign; his brother John Podesta, who became Clinton’s White House chief of staff; Sam Gejdenson, who represented Connecticut in the US House from 1981 to 2001; Michael Medved, who became a conservative radio host; and Larry Kudlow, who became a Wall Street economist, financial commentator, and director of the National Economic Council under President Trump.

‘‘It was the all-star team of that era,’’ Tony Podesta said in a phone interview. ‘‘Everybody wanted to be there because of their respect for Joe and their admiration and willingness to follow Anne wherever she wanted to go. It didn’t even feel that much like a campaign. It was a movement.’’

The staff was aided by actor and Connecticut resident Newman, who co-chaired the campaign and drummed up publicity, as well as by a finance committee that included writers and artists such as Alexander Calder, William Styron, and Thornton Wilder.

Dr. Duffey blamed his defeat partly on the late entrance of an independent candidate, Thomas J. Dodd, the Democratic incumbent. The father of five-term senator Chris Dodd, he had been censured by his Senate colleagues in 1967 for diverting political contributions for his personal use. His campaign split the Democratic vote, helping deliver a victory to Weicker, who won nearly 42 percent of the vote.

‘‘In those days, it was really a war in this country,’’ Dr. Duffey told the Hartford Courant in 1993, shortly before Clinton’s inauguration. ‘‘It was between young people in college and blue-collar working people. My campaign was an effort to identify that and try to overcome that.’’

The oldest of five children, Joseph Daniel Duffey was born in Huntington, W. Va., on July 1, 1932. His father lost a leg in a coal-mining accident and became a barber, and his mother died when Joseph was 13.

Raised in the Baptist church, he served as a church assistant and went to youth conventions, where he met Patricia Fortney. They married in 1952, when he was 19. After the Senate election, he and Wexler divorced their respective spouses, marrying in 1974.

Dr. Duffey received a bachelor’s degree in 1954 from Marshall University in Huntington. He completed his theological studies with a bachelor of divinity from Andover Theological Seminary in 1957, a master’s degree from Yale Divinity School in 1963, and a doctorate from Hartford Seminary Foundation in 1969.

After heading Carter’s Washington office during the 1976 presidential campaign, he was appointed to the State Department, as assistant secretary for educational and cultural affairs. Later in 1977, he was named chairman of the National Endowment for the Humanities, taking charge of a federal agency that supported projects ranging from the development of new encyclopedias to the release of educational television series.

As chancellor of the University of Massachusetts Amherst, he spearheaded the rollout of a new general-education curriculum for undergraduates. Richard O’Brien, who served as provost and later succeeded him as chancellor, credited Dr. Duffey with revitalizing the university’s business school and helping to bring UMass Amherst ‘‘out of the shadows.’’

‘‘It became much more of an international place than when he inherited it,’’ he said.

For about a year before Dr. Duffey left the school, in 1991, he also served as president of the statewide University of Massachusetts system. He resigned both positions to become president of American University.

Clinton tapped him in 1993 to run USIA, an agency that promoted US policies overseas before being abolished six years later, with most of its functions taken over by the State Department.

Dr. Duffey ended his career as a senior vice president at Laureate Education, which owns a network of for-profit colleges abroad.

His wife died in 2009, and a son from his first marriage, David, died in 2019.

In addition to his son, Michael, Dr. Duffey leaves his companion, Marian Burros, a longtime food writer at The New York Times and former editor at The Washington Post; two stepsons, Daniel and David Wexler; two sisters; and four grandchildren.

A few weeks before his death, Dr. Duffey celebrated the 50th anniversary of his Senate campaign with a virtual reunion on Zoom, held with Clinton and other former campaign staffers. When they last gathered, at Clinton’s inauguration in 1993, Dr. Duffey warned against romanticizing the 1970 campaign and that period in the country’s history.

‘‘It was so divisive, with one generation pitted against another,’’ he said, according to a Los Angeles Times report. Still, he added, ‘‘What we all sensed then was what Bill Clinton sensed last year, that politics can either divide people or bring them together.’’