In his first solo appearance as the Democratic candidate for vice president of the United States, Tim Walz flew to Los Angeles to appear before 4,000 members of the American Federation of State, County and Municipal Employees (AFSCME), one of the most powerful and engaged labor unions in the United States. Walz, for many years a dues-paying member of two public-sector labor organizations, the National Education Association and the American Federation of Teachers, thanked the assembled delegates for “having a fellow union member” as their convention speaker and declared, with as much passion as a Minnesotan can muster, that “AFSCME stands for all that’s right.”

That wasn’t political small talk of the sort that candidates engage in when they are simply tapping the bases of constituent groups in their coalitions. That was a sincere expression of gratitude from a former member of Congress and a governor who has relied on the support of AFSCME—a 1.4 million-member union with a long history of identifying and supporting rising stars in the Democratic Party—to win his own elections, and to help him make Minnesota what Walz describes as “one of the best states for workers in the nation.”

Walz’s connection with AFSCME runs deep. Like Democratic presidential nominee Kamala Harris, he has high regard for the union’s president, Lee Saunders, who for many years has chaired the political committee of the AFL-CIO, served on the Democratic National Committee, and built a reputation as a uniquely savvy and influential political strategist and policy advocate. A working-class intellectual who trained as a labor economist but has always maintained the enthusiasm of a grassroots organizer, Saunders sees organized labor in the context of broader movements—he’s long been active with the Leadership Conference on Civil and Human Rights, a group he currently serves as treasurer—and progressive governance.

Recalling their history together, Walz said of Saunders, “We’ve done a few door knocks, we’ve done a few phone banks, we’ve done a few rallies, and we’ve worked together on a few laws to improve people’s lives.” Hailing the union president as “the friend to every American worker”—those who have organized as union members and those who have yet to organize—Walz said Saunders and AFSCME understand the basic premise of progressive trade unionism: “you don’t win elections to bank political capital to win another election; you take that political capital and you burn it as fast as you can to improve people’s lives.”

Presidential campaigns do not do many things by accident. The decision to have Walz start his solo campaigning with AFSCME sent a message that the Democratic ticket wants to maintain the tight relationship that the movement developed with Joe Biden, a labor favorite who liked to assert that he was the most pro-union president in modern American history.

In an exclusive Labor Day interview with The Nation, Saunders said that the Harris-Walz ticket had generated “a level of excitement that I haven’t seen for a long time.” He also expressed his confidence that Harris and Walz would pick up where Biden left off.

“We know her not only from being the vice president, but we know her from when she was attorney general in California—and the work she did with childcare and home care and the care economy,” Saunders recalled. “She was a partner with President Biden, when she served as vice president; and we have complete faith and trust in what she will do to move this country forward. By the same token, I have known, very well, Tim Walz as the governor of Minnesota. We have two very strong affiliates in that state. I go to that state very often, and I always see him and talk to him. There is no question in my mind that this is a team that will fight for working families. They will crisscross the country to do what they need to do to motivate people, to educate folks, to mobilize folks around the importance of this election. We’re very excited about it. Our members are very excited about it. The labor union movement, the trade union movement, is very excited about Harris and Walz.”

That excitement is evidenced in the backing the Democratic ticket has secured from the AFL-CIO and most of the high-profile unions that are associated with the federation. In addition to support from AFSCME—which has members organized across 3,400 local unions and 58 councils and affiliates in 46 states, the District of Columbia, and Puerto Rico—the Harris-Walz ticket has won endorsements from the Service Employees International Union, the American Federation of Teachers, the National Education Association, the Communications Workers of America, the United Steelworkers, the Laborers International Union of North America, the International Brotherhood of Electrical Workers, the International Union of Painters and Allied Trades, the International Union of Operating Engineers, National Nurses United, and dozens of other international unions, labor federations, and locals across the country. Vital support has also come from the United Auto Workers union, which is an especially influential force in the battleground states of Michigan, Wisconsin, and Pennsylvania.

The ticket is still working to secure the backing of two key unions, the International Brotherhood of Teamsters and the International Association of Fire Fighters. Walz made his pitch to the firefighters on Wednesday at their convention in Boston, saying to the cheering crowd, “Sisters and brothers in labor, it’s time for you to step up to the plate.”

The Democratic outreach to labor is more than a messaging exercise. It reflects the reality that unions are an essential base of political—and practical—support for the party. That was certainly the case in 2020, when Biden defeated Trump by 7 million votes nationally and retook three historic union states—Wisconsin, Michigan, and Pennsylvania—that had been narrowly carried by Trump in 2016. Biden has worked hard to maintain the relationship, regularly meeting with and taking the counsel of labor leaders, appointing labor allies to key positions, and advancing a pro-worker agenda even as he has faced very nearly uniform opposition from congressional Republicans and splits in the ranks of the Senate Democratic Caucus. And Harris has been at the president’s side every step of the way, said Saunders.

“She was a team player,” he said of the Biden-Harris partnership. “She was his vice president and she was instrumental in helping to move a lot of the important legislation—along with President Biden—that supported working families. You look at the relief plan, where she was the tie-breaking vote. You look at the infrastructure plan, where she was the tie-breaking vote. She was really a partner with President Biden, and we know for a fact that she is going to continue to support working families all across the country. Union people are excited about it. And, now, with Tim Walz, I think it’s a dynamic duo.”