Dave Durenberger, who served 16 years in the U.S. Senate as a moderate Republican and championed affordable health care, the Boundary Waters and the Americans with Disabilities Act, died Tuesday. He was 88.

His son Dave Durenberger Jr. said his father declined in the past two weeks and died at his St. Paul home. "That's what was so wonderful about all of this; it was a two-week process and family was able to come and be with him and tell stories," his son said.

Born in St. Cloud in 1934, Durenberger grew up on the campus of St. John's University in Collegeville, where his father, George Durenberger, was the athletic director and his mother, Isabelle, was a longtime administrative assistant who helped found the alumni organization.

Ambitious, and with hopes of becoming governor, Durenberger was the top cadet in his ROTC class at St. John's, a lieutenant in the U.S. Army Counter Intelligence Corps and a captain in the U.S. Army Reserve. He earned his law degree in 1959 from the University of Minnesota.

He was drawn to politics early, working for former Govs. Harold LeVander and Elmer L. Andersen. In the late 1970s, he launched his own gubernatorial bid, but when DFL Sen. Hubert H. Humphrey died in January 1978, Durenberger ran for Humphrey's Senate seat with a campaign theme of "Minnesota's Next Great Senator."

He won and held the seat until 1995 when he didn't seek re-election after a scandal over his congressional expense account. He remains the only Republican from Minnesota to be elected to three terms in the U.S. Senate. His longtime chief of staff Tom Horner said Durenberger's guiding concern was, "How do I have government that is efficient, effective and as close to the people as possible?"

Durenberger's fingerprints were on many sweeping pieces of legislation affecting health care, the environment and people with disabilities, and he continued his work after leaving office as the chair of the National Institute of Health Policy and a senior health policy fellow at the University of St. Thomas in St. Paul.

"Today our country lost a patriotic American, Minnesota lost a skilled statesman, and Saint John's lost a great Johnnie," St. John's President Brian Bruess said in a statement.

On Friday, Bruess visited Durenberger and presented him with the university's presidential medal of honor. When the former senator heard about the visit, he "perked up, put on his St. John's pullover and said, 'Go Johnnies,'" his son Dave said. "He's just always been the kind of guy who would do what he had to do."

Durenberger said his father would want to be remembered mostly for the passage of the Americans with Disabilities Act because it leveled the playing field and removed barriers for millions. "He was so proud of that," his son said.

His father had a global network of friends and could connect with anyone, Dave Durenberger said. "He didn't judge people by what they looked like or what party they belonged to or how much money they had."

As they looked at old photographs, his son said the one that struck him showed his father beaming after having put a medal around the neck of a Special Olympian swimmer with Down syndrome and leaning in to give her a kiss. "That's Dad," Dave Durenberger said.

The former senator also successfully pushed for protections for the Boundary Waters Canoe Area Wilderness, Voyageurs National Park, the Mississippi River and Twin Cities-area parks and trails.

In 1993, he and the late Democratic Sen. Paul Wellstone worked across the aisle to pass the National and Community Service Trust Act establishing AmeriCorps, a government agency that taps 200,000 volunteers annually to work with nonprofits across the country.

The U.S. Senate censured Durenberger in 1990 for ethics violations related to evading $100,000 limits on speaking fees and using his own Minneapolis condo to collect $40,000 in travel reimbursements. The state Supreme Court suspended his law license in 1991 but reinstated it in 2000.

Durenberger did not run for reelection in 1994, and a year later he pleaded guilty to five misdemeanor charges involving the abuse of his account. "Both personally and professionally, this is a matter I had to get behind me," Durenberger said at the time. He was sentenced to one year of probation.

He left the Republican Party in 2005 and endorsed the presidential campaigns of Democrats Hillary Clinton in 2016 and Joe Biden in 2020. He didn't join the Democratic Party but was a harsh critic of Republicans until the end.

Last August when he spoke at a gathering for his 88th birthday, Durenberger lamented the frequent comments of a Republican gubernatorial candidate about government getting "the hell out of the way."

That view of government "is antithetical to my core values," Durenberger said. "In this grand democracy, government is not a nuisance, not an evil force. People elect public servants. I learned from my family, from my education at St. John's, and in all the years since then, the shared value of civic engagement."

Horner said Durenberger viewed the candidate's statement as a "complete betrayal of the Republican principles he grew up with" and that the senator believed "we ought to have government there for the times when people are most vulnerable."

Democratic Sen. Amy Klobuchar said Durenberger showed her immense kindness and encouraged her to join the Senate's weekly prayer breakfast. "I am grateful I did," she said in a statement. "He also told me that despite the many hurdles, working to improve people's health care is always worth it."

Durenberger and Lori Sturdevant, a former Star Tribune editorial writer, wrote a book called "When Republicans Were Progressive," published in 2018 by the Minnesota Historical Society Press. A reviewer for the Star Tribune described the book as a "nostalgic look back at bipartisanship among political parties, a cri de coeur about current ugly electoral politics, a platform for positive change and a skimpy yet alluring look into his personal life."

He is survived by his wife of 27 years, Susan Foote; four sons; two stepchildren and 14 grandchildren. He was preceded in death by his first wife, Judy, who died of breast cancer in 1970 when their four boys were young. His sons are Charlie and his wife, Lois, of Lindstrom; Dave and his wife, Heather, of Chanhassen; Mike and his wife, Maggie, of St. Paul and Dan and his wife, Jennifer, of Shelbyville, Ky. Durenberger's stepchildren are Becca Greenwald of San Anselmo, Calif., and Ben Foote of Edina.

In the wake of losing their mother, Dave Durenberger said their father loomed larger than life to them and they hung on every word. "We just loved him so much and wanted to be with him," the son said.

Their father was active with their swim team, and they helped him stuff envelopes at the kitchen table and attended campaign events. In recent years, he was an active grandfather who attended school and sports events.

Durenberger married Penny (Thuet) Baran in 1971. They divorced in 1995.

He is also survived by four siblings: Connie Kneip of Milwaukee, Mark Durenberger of Edina, Tom Durenberger of Mesquite, Nev., and Mary McLeod of Tulsa.

Visitation will be Tuesday at 8:30 a.m. at St. John's Abbey Church in Collegeville, followed by services at 10 a.m. and a private burial.

The funeral will be livestreamed.