May Day this year provides an occasion for both workers and anti-Trump and anti-oligarch protesters to take to the streets. But May Day should also be a reminder of what it takes for workers to actually gain a say in their work lives and the pay and security essential to decent living standards: strikes.

It’s not a coincidence that the three decades in American history in which the nation’s prosperity was broadly shared, even among many blue-collar workers, were the 30 years in which workers’ strikes were routine: roughly 1945 to 1975. In the 1950s, the average yearly number of major strikes (those involving at least 1,000 workers) was 352; in the 2010s, it was a bare 16. That precipitous decline was both cause and effect of the shrinking share of unionized American workers. It was also due to Ronald Reagan’s 1981 firing of the nation’s air traffic controllers, which prompted a slew of CEOs to fire their own strikers and threaten those who were merely thinking about it with kindred discharges. The shift from a manufacturing to a service economy also meant a shift from large and centralized to smaller and widely dispersed worksites. When the fledgling UAW shut down three key General Motors factories in the winter of 1937, it crippled production at the other 20 or so GM factories. Today, however, Amazon has close to a thousand domestic warehouses; Walmart has a good deal more than a thousand stores; and Starbucks owns 9,000 coffee outlets. The baristas of Workers United have unionized about 550 of them through a brilliant and tenacious campaign, but they’d have to have unionized more like 5,500 of them to wage a strike that compelled management to sign a decent contract.

And yet, there are signs that the strike is coming back—at least, selectively. On Tuesday and Wednesday of this week, 55,000 employees of Los Angeles County government—librarians, social workers, maintenance personnel—staged a two-day strike to push the county to agree to a contract that would enable them to catch up, at least partially, with L.A.’s soaring costs of living. (Los Angeles, after all, ranks as the city where the gap between median incomes and median housing costs is the greatest.) That so many workers were able to visibly demonstrate—thereby compelling normally celebrity-besotted local newscasts to cover the protests—was a testament to worker militance and worker need, and to their parent union’s fusion some years ago of seven disparate locals into one big local. (The local is SEIU 721—“seven to one,” get it?)

Just as the UAW waged perhaps the most important strike in U.S. history in 1937 (its victory kicked off the mass unionization of the nation’s major manufacturers), so it also waged a brilliant “Stand Up” strike against GM, Ford, and Stellantis in 2023, rotating walkouts against particular factories that compelled the companies to agree to the first good contract the workers had won in many years. That said, causing shutdowns at a dozen or two key factories in an industry where the Big Three combined have fewer than 100 domestic plants yielded a significant victory, as causing shutdowns at a dozen or two Walmarts or Starbucks would not. For years, unions have worked at unionizing key links in major retailers’ supply chains—for instance, the truckers who move imports from the ports to the retailers’ warehouses—as a way to bring the Walmarts and Amazons to the table. That’s still a work in progress.