– Walter Mondale successfully threaded a brand of Hubert Humphrey liberalism into the fabric of national politics in the 1970s and ’80s, leveraging his Midwestern honesty and Minnesota’s then-importance as a battleground state to gain political prominence.

Or, as the former vice president himself said in a quote now etched at the Carter Presidential Library: “We told the truth, we obeyed the law, we kept the peace.”

Mondale’s lasting mark on American politics is now bringing together political luminaries, including former President Jimmy Carter and Vice President Joe Biden, who are converging in Washington this week to celebrate his legacy and bring fresh attention to his passion for social justice.

“He’s always stayed relevant,” said Sen. Amy Klobuchar, D-Minn., who as a law student interned for Mondale while he was vice president. “He has never left his Minnesota roots, and he always wants to talk about politics locally and nationally … He keeps going.”

Tuesday’s D.C.-based events will culminate a year’s worth of work at the University of Minnesota’s Humphrey School of Public Affairs honoring Mondale, which included a $2 million fundraising campaign for student scholarships. They’ll feature panel discussions on some of Mondale’s favorite topics — social justice, national security, the U.S. Constitution and civil rights.

“It’s an honor to be able to pull together an impressive group like this,” he said. “They’re all friends of mine, and with President Carter attending, it adds a special level of significance.”

Besides Carter and Biden, Sens. Klobuchar, Al Franken, Dianne Feinstein and Patrick Leahy will participate, as will Gov. Mark Dayton.

A passion undimmed

At 87, Mondale is still known for checking in with Minnesota politicians, no matter how busy they are, just to gossip. He is still known for coaching the most eager and accomplished young people on his belief that a life in public service takes dues-paying and grunt work.

Mondale and Carter, who is 91, are together the longest-living presidential team since John Adams and Thomas ­Jefferson.

Carter and Mondale’s friendship and political stature only grew after they served a single term together. Carter lost his bid for re-election to Ronald Reagan in 1980, and Mondale’s bid to knock off the charismatic former actor resulted in a landslide defeat four years later.

Mondale said he still talks to Carter a few times a year and recently flew to Georgia to have a private dinner with the former president and his wife, Rosalynn, after hearing that ­Carter’s melanoma had metastasized to his liver and brain.

In 2002, Mondale agreed to run for former Sen. Paul Wellstone’s Senate seat after Wellstone died in a plane crash 11 days before the election. He narrowly lost to Republican Norm Coleman.

He also served as U.S. ambassador to Japan from 1993 to 1996, during Bill ­Clinton’s presidency.

A broad influence

Klobuchar has dozens of favorite Mondale stories, often focused on his desire to instill a sense of humility.

She recalls how he made her inventory hundreds of pieces of furniture in the vice president’s office when she was an ambitious law school intern.

Or the time at the 2004 Democratic convention that he insisted she memorize her speech because teleprompters were known to blink out. She dutifully followed his advice, and right before she was about to take the stage, the teleprompter died, sparking a famous “I told you so” smile from Mondale, who was watching in the audience.

U.S. Rep. Rick Nolan, who worked for Mondale in 1966, said the former vice president rightfully talked him out of running for Congress at the time and instead told him to go back to Minnesota and get some local experience.

“He said, ‘If you run now, you will win the endorsement, but you may lose the election,’ ” Nolan said. “I was someone who was all fired up and ready to go. It was not what I wanted to hear, but I listened carefully.”

Mondale, who still works a few days a week at a Minneapolis law firm, finds it difficult to talk too much about himself. But he was quick to answer what current American issue he most worried about — the shrinking middle class and unfettered money in politics.

“The grip that big money has on the American political system frightens me,” he said.

‘So much to say about him’

Eric Schwartz, dean of the Humphrey School, said no figure has played a bigger role in the life of the school — and perhaps modern-day Minnesota politics — than Mondale.

Schwartz said when he told Mondale that they wanted to honor him, the former vice president insisted on making it a fundraising effort to help students “who share his commitment to making the world a better place.”

“For me personally, I think it’s his deep dedication to economic and social justice, and to civil rights, and to transparency in government,” said Schwartz. “I think there really is so much to say about him.”