Paul Wellstone was a movement progressive. From the farm crisis days when he was organizing rural Americans to fight back against corporate agribusiness to the last days of his final campaign, Wellstone worked to forge a left that was muscular enough to win elections, to govern and to bend the arc of history toward justice.

But the senator from Minnesota was not afraid to stand alone, if that was what principle demanded. Just days before his death on October 25, 2002, he was the only US senator facing a seriously competitive reelection race to vote against authorizing George W. Bush and Dick Cheney to launch an invasion of Iraq.

Ten years after America lost the great progressive populist in a plane crash that claimed his remarkable wife, Sheila, their daughter, Marcia, two pilots, a driver and two campaign staffers, it is Wellstone’s courageous anti-war vote that is best recalled. And rightly so. Paul called me when he announced that he would oppose the Bush-Cheney administration’s rush to war. He was upbeat, proud and confident. He knew he had taken what Washington insiders believed to be a political risk, but he was betting on the common decency and the common sense of Minnesotans. And the polls circulating at the time of his death confirmed Wellstone’s political instincts were every bit as sound in 2002 as they had been in 1990—when he bet that a quirky, low-budget campaign run from the back of a green school bus and relying on a television ad that mimicked Michael Moore’s anti-corporate documentary Roger and Me could unseat a millionaire Republican senator.

That was Paul’s genius. He understood that, sometimes, perhaps most times, Americans respect a stand on principle. And he recognized that time often turns the isolated concern of the true believer into popular sentiment. Paul disliked the suggestion that he was a “maverick.” He might break with presidents of his own party, with Democratic leaders in the Senate, but he did not do so for headlines. He did so because he felt it was morally and practically necessary for what he called “the democratic wing of the Democratic Party” to be heard.

This was particularly the case when it came to defending the interests of the working poor. Paul did not anger easily. But he truly, totally, despised the notion that budgets could, or should, be balanced on the backs of the poor and the working class. When the privileged exploited their economic advantages and lobbying connections to write the laws of the land, Wellstone was more than willing to stand alone in opposition.

That was the case in the late 1990s and early 2000s, when the Senate was considering bankruptcy law “reforms” designed by bankers and credit company CEOs to take away protections that were essential to the working poor. Wellstone fought the corporatists and the politicos to make the law more humane and responsible. And when his fellow senators refused to rewrite it, he rejected it. Ninety-seven senators voted on September 23, 1998, for a noxious version of bankruptcy reform. One senator, Wellstone, voted “no.” (There were more “no” votes in the House, coming from, among others, Vermont Congressman Bernie Sanders and Ohio Congressman Sherrod Brown, both future senators.)

Over the next few years, Wellstone would emerge as the champion of a humane and responsible approach to reform that understood, as he said, that “the bankruptcy system is a critical safety net for working families in this country. It is a difficult demoralizing process, but for nearly all who decide to file, it means the difference between a financial disaster being temporary or permanent. The repercussions of tearing that safety net asunder will be tremendous, but the authors of the bill remain deaf to the chorus of protest and indignation that is beginning to swell as ordinary Americans and members of Congress begin to understand that bankrupt Americans are much like themselves, and that they are only one layoff, one medical bill, one predatory loan away from joining the ranks.”

At his side through the struggle was an initially little-known Harvard Law professor, Elizabeth Warren, who had developed an expertise on bankruptcy issues as an adviser to the National Bankruptcy Review Commission. As legal scholar Kristin Brandser Kalsem notes, Warren was “engaged in a pathbreaking campaign to call attention to the fact that those concerned about women and women’s issues should be paying attention to bankruptcy reform and other economic legal issues.”

Wellstone introduced me to Warren in those days, and constantly referenced her academic studies and her activism. He cherished her as an ally in a lonely struggle. Indeed, when he cast those lonely votes, he would joke about his political isolation, saying he could use ten more progressive senators—or, at the least, one Elizabeth Warren.

That was how Paul thought. He could imagine college professors becoming senators. After all, he had made the leap.

Now, a decade after Wellstone’s death, his old partner in the fight for justice for working families, laid-off workers and struggling homeowners is running for the Senate from Massachusetts. It is hard to imagine any political development that would have delighted Paul more. Wellstone loved to campaign, not just for himself but for others. He’d surely be campaigning this fall for old friends Sherrod Brown in Ohio and Bernie Sanders in Vermont this year, as he would be for his frequent ally Tammy Baldwin, who is seeking a Wisconsin Senate seat. And you can bet that the happy warrior of modern American progressivism would be working  Massachusetts, from Pittsfield to Provincetown, for Elizabeth Warren. After all, he recognized, long before the rest of us did, that she was needed in the Senate.

Check out Nation editor and publisher Katrina vanden Heuvel on the legacy of Paul Wellstone.