Sen. Orrin Hatch in Washington, 2018.

Photo: Michael Brochstein/Zuma Press

As the American body politic splintered over the past decade, some dedicated men and women worked to keep left and right together. This week we mourn one of those leaders. The “gentleman of the Senate” and one of the most prolific lawmakers in American history, Sen. Orrin G. Hatch, who died Saturday at 88.

I worked with Hatch for more than 15 years as Senate Judiciary Committee senior counsel and his final chief of staff. The man represented a generation of lawmakers brought up on the virtues of bipartisanship and compromise. He was beloved by colleagues on both sides of the aisle, making him an anomaly in polarized times.

So what was the secret to his success? How did a strong conservative from the American West earn the love and admiration of liberal icons like Ted Kennedy and Ruth Bader Ginsburg ? How did he transcend the traditional boundaries of right and left to become one of the most successful legislators of all time?

It’s impossible to distill into a few hundred words the wit, grit, charm and empathy that led to Hatch’s success. But today’s leaders would do well to emulate his unique style of politicking.

In contrast with the stock image of the country club Republican, Hatch was what I like to call a “ Costco Republican.” The wholesale giant was his favorite hangout on weekends. Ask anyone who knew him: Costco was the only club membership he ever really cared about. He would go there every recess for Kirkland Signature dress shirts (yes, the same $19.99 dress shirts he would wear on the Senate floor) and a Costco hot dog (a personal favorite of his).

But the real purpose behind his Costco trips was to rub shoulders with everyday Utahns. In other words, Orrin’s people—the men and women who make up the backbone of America’s communities. Hatch knew that if he lost touch with them, he would lose touch with himself and who he was: the scrappy son of a Pittsburgh steelworker who, through luck and skill, happened to find himself in the U.S. Senate.

When it came to legislating, Hatch was a master of the long game. While many politicians measure time in days and news cycles, he thought in years and decades. As a relatively new staffer, I coordinated with other Senate offices to pass intellectual-property legislation. But at the last minute, negotiations stalled, and our bill’s chances were shot down.

Outside the Senate cloakroom, Hatch caught me looking dejected and frustrated—but didn’t let me stay that way long.

“What’s your problem? You thought we were going to pass this legislation today?” he asked with a smile. “We’ll get this thing passed, but this is only the beginning. Remember, we’re playing the long game here. This is a multi-Congress kind of bill.”

He was right. Congress enacted the bill years later. Some of Hatch’s greatest legislative accomplishments, including the Children’s Health Insurance Program and the Religious Freedom Restoration Act, were the culmination of many years of work.

Hatch approached constituent service with the same patience, perseverance and dedication. The story of Josh Holt is a vivid example. Mr. Holt, a native Utahn, was arrested by Venezuelan authorities under false charges in 2016 and endured months in prison. Hatch worked with three different secretaries of state and Presidents Obama and Trump to secure Mr. Holt’s release. I was sitting beside Hatch when he spoke on the phone with Venezuelan President Nicolás Maduro and persuaded him to agree to the release. Like many politicians, Mr. Maduro got the Orrin Hatch treatment. That happened when unyielding partisans found themselves negotiating with a man they were programmed to despise but ended up liking so much they went along with his plan.

This was one of Hatch’s greatest strengths. People could vehemently disagree with his politics, but it took a herculean effort to dislike the man. That helped him make unlikely but strong friendships, including with Muhammad Ali

(who asked Hatch to speak at his funeral), Sen. Kennedy (who considered him one of his closest friends in the Senate, and Justice Ginsburg (whom Senator Hatch recommended to President Clinton for the Supreme Court and who attended Hatch’s Presidential Medal of Freedom ceremony).

Hatch showed how to work outside the political culture of extreme polarization. Fight when necessary. But do so with dignity, showing respect for your opponent. And always remember politics is the art of persuasion, not humiliation.

That was the Hatch way. That was how he got his colleagues to yes on some of the most significant policy reforms in our nation’s history, such as Hatch-Waxman, which helped created the modern generic drug industry. And that was how he retired having passed more bills into law—750—than anyone alive at the time.

My experiences with the man and the insights he shared during his final decades of public service allow me to say this: If every member of Congress had the wisdom, character, integrity and foresight of Orrin Hatch, our country would be stronger, more prosperous, and more united today. May our nation’s leaders honor his legacy by following his example.

Mr. Sandgren is executive director of the Orrin G. Hatch Foundation. He served as a senior counsel on the Senate Judiciary Committee and as Sen. Hatch’s chief of staff.