Almost a half-century ago, hoping to prod a young president who meant well but kept missing the mark when it came to implementing bold economic and civil rights initiatives, United Auto Workers president Walter Reuther aligned the most muscular labor organization in the land behind an audacious call by veteran trade unionist A. Philip Randolph and young civil rights leader Martin Luther King Jr. for a "March on Washington for Jobs and Freedom." Reuther’s personal commitment provided resources, a national network of supporters and help opening doors at the Capitol and the White House. While much of Big Labor resisted the sit-ins, marches and mass protests that would define the 1960s as a period when politics was not just in the voting booths but in the streets, the UAW was in touch with the civil rights and antiwar movements of the moment.

Reuther is long gone and the UAW, battered by decades of free trade policies and flawed federal economic agendas, is down to 390,000 members, barely a quarter of its peak size in the 1970s. And while pretenders like Glenn Beck pervert the memory of that 1963 March on Washington and the campaigns that followed it, genuine heirs to the activist movements with which the union allied struggle to move economic, social and foreign policy debates in a progressive direction.

Enter Bob King. The new UAW president has dusted off the still-substantial union and renewed its activist tradition by building coalitions—in late August, the UAW joined the BlueGreen Alliance of labor unions and major environmental organizations in pursuit of good jobs, a clean environment and a green economy—and supporting mass-movement projects like the August 28 Jobs, Justice and Peace march in Detroit. King’s election in June signaled a Reuther turn for the union, with the new president declaring, "Our mission is social justice…. We have the resources that we have to share, to fight for, to be part of a much broader struggle [of] workers inside our facilities and outside, inside the UAW and outside. The only way we can have social justice for our membership is to fight for social justice for everybody in society."

That’s not just rhetoric for King, who comes out of historically militant UAW Local 600 in the Detroit area, where he practiced international solidarity in the 1980s by organizing opposition to Reagan administration policies in Latin America—King still attends annual protests to close the former School of the Americas in Fort Benning, Georgia—and South Africa’s apartheid regime. (I met King in the early 1990s, when a recently released Nelson Mandela toured a Local 600 plant to thank UAW members for their support of the freedom struggle.)

King has an ambitious agenda for the UAW; it includes organizing US manufacturing plants operated by foreign firms such as Toyota and restoring pay and benefits lost when the UAW agreed to cuts as GM and Chrysler were sputtering. The union leader took hits for negotiating givebacks and a loosening of work rules at Ford, and he is still criticized for talking about "partnerships" with the Big Three. But King answers that the challenge of saving basic industries requires building broad coalitions for workplace fairness and fair trade policies designed "so that corporations [cannot] use low wages, poor working conditions and repression of unions to their competitive advantage."

King is taking the UAW back to the streets. Days after his election, he and the Rev. Jesse Jackson announced a campaign to: "1. Rebuild America by enacting industrial and trade policies that will create jobs, encourage manufacturing in America and put workers first. 2. Enforce the law regarding workers’ rights, civil rights, industrial regulation, and creation of fair and just educational, economic, and health policies. 3. End the ongoing wars in the Middle East and redirect the war budget to rebuilding America."

The campaign, which has attracted support from labor, civil rights, religious and political leaders, debuted with the August 28 commemoration in Detroit of the 1963 Walk to Freedom, where a crowd of 125,000 heard Dr. King’s first recitation of his "I Have a Dream" speech. It was a perfect counterpoint to Beck’s attempt, the same day, to claim a piece of the civil rights legacy; and Jackson, who this summer marked the fiftieth anniversary of his first sit-down protest, has thrown himself into the project. Frustrated, like many progressives, with the failure of a Democratic administration and Congress to move as aggressively as needed, the Rainbow/PUSH Coalition leader has been looking for ways to combine electoral and street-protest politics as a populist counter to the Tea Party movement, arguing that "Marching is not incidental to progress. Marching matters. Marching inspires."

Jackson and Bob King plan to keep marching and rallying. Jackson will headline the Fighting Bob Fest, on September 11, the annual gathering in Wisconsin named for former Senator Robert La Follette, which draws as many as 10,000 activists. It’s part of a busy schedule of building momentum for the October 2 March on Washington, which has rallied the UAW and other major unions, as well as civil rights groups like the NAACP and the National Council of La Raza, behind a call to "demand the change you voted for." Echoing Jackson—and Walter Reuther—King says, "If you don’t keep marching, you start losing. We will march until we win."