In mid-February, as thousands of people were pondering what to do about a midweek “Day Without Immigrants,” one of them called up a union office in Chicago to ask if he should call in sick when going on strike for the day. “You can’t say you are calling in sick. You’re on strike!” replied an agitated union official. “If you are calling in sick, you’re just sick.”

This little bit of confusion illuminates larger and more important questions facing all those seeking the best way to protest President Trump, the GOP-led Congress, and the immigration, health care, and environmental polices the new administration seeks to impose upon a reluctant populace: what is the meaning of a strike, demonstration, or protest march?

Is it designed to register a vast outpouring of sentiment, as was so magnificently demonstrated in the women’s marches and assemblies held all across the country the day after Trump’s inaugural? Or are these protests really more like a political strike, designed to show that many workplaces (indeed, the entire functioning of a complex society), will be crippled, at least for a day, when both immigrants and those who support them don’t show up at work? That was the message put forward on Thursday, February 16 when thousands of workers shut down hundreds of restaurants, warehouses, retail shops, and garages in a work stoppage and boycott labeled “A Day Without Immigrants.”

Most recent marches and demonstrations don’t have much impact at work. They are often held on a Saturday at a location far away from residences and workplaces. But this weekend protest tradition is actually of relatively recent origin, with an unexamined politics and strategic outlook that has weakened the very impact of the cause those participating seek to advance. While more people might be expected to show up on a Saturday, the potency of their protest is diluted by creating a divide between what people do in the arena of politics and how they conduct themselves in the world of work.

In the nineteenth century and for decades after, one could hardly make such a distinction. A demonstration, a strike, and a march were all part of the same protest. Workers in tightly packed industrial districts “turned out” of their factories and mills, marching by neighboring worksites and calling on their mates to down tools and join the parade.

In their demand for a shorter workday, union recognition, or higher wages, they sought not just to stop production, but to occupy the public square — civic space — in order demonstrate their power both as workers and rights-bearing citizens. Thus did the women of the antebellum Lowell Mills declare themselves “daughters of freemen” in protest against the “Lords of the Loom and the Lords of the Lash.” Clashes with the police or militia were frequent because the local bourgeoisie were just as determined to deny such public legitimacy to a proletariat organizing itself for political and economic combat. In the 1930s and 1940s when the industrial unions were on the rise, the biggest demonstrations also shut down factory districts in Detroit, Chicago, Akron, Oakland, the garment district of Manhattan, and other industrial hubs.

In Detroit, tens of thousands of autoworkers filled Cadillac Square in a series of region-wide general strikes that were as much political as economic in their demands. In April 1937, the United Auto Workers (UAW) emptied scores of factories to protest police assaults on female sit-down strikers then occupying department stores and smaller industrial establishments.

After the war, in July 1946, the UAW again filled downtown Detroit, with fifty thousand striking workers, to demand the continuation of war-era price controls on meat, milk, and consumer goods essential to working-class families. And just fifteen months later, on April 24, 1947, the autoworkers shut down Chrysler, Ford, and many other factories in the city to fill Cadillac Square with more than a quarter million people protesting the anti-union Taft-Hartley Act then pending in Congress.

This demonstration, on a Thursday, was by far the largest in US history up to that point. But it was much more than a large assemblage — as one union leader forecast, it seemed to open up an era of class-wide general strikes, deploying “the kind of political power which is most effective in Europe.”

McCarthyism, broad prosperity, and the routinization of collective bargaining ended that prospect, but the understanding that demonstrations should have a working-class dimension was not lost on those, like the African-American unionist A. Philip Randolph, who organized the 1963 March on Washington for Jobs and Freedom. That demonstration was held on Wednesday, August 28, 1963. The organizers, who included many from the ranks of labor, as well as the civil rights leadership, did not intend to shut down work in Washington, DC. But that is exactly what the march accomplished.

“At 8 AM,” reported journalist Russell Baker, “when rush-hour traffic is normally creeping bumper-to-bumper across the Virginia bridges and down the main boulevards from Maryland, the streets had the abandoned look of Sunday morning.” Many African-Americans in government employment and elsewhere undoubtedly skipped work to join the march. But of the 160,000 federal and city employees, most were white and a majority of them stayed home, while nearly half of local businesses were closed.

White tourists also avoided the city, leaving many hotel rooms vacant. As in the nineteenth century, the occupation of the public sphere and space by a supposedly alien army had proven profoundly disquieting to those accustomed to the deference and invisibility of that social force.

“For the natives,” Baker wrote, “this was obviously a day of siege and the streets were being left to the marchers.”

Ironically, it was the generation of self-consciously radical young people, organized into the Students for a Democratic Society, who ended the century-long tradition that linked demonstrations, marches, and the world of work.

When SDS leaders planned the first big protest against the war in Vietnam, a march down the National Mall from the Washington Monument to the Capitol, they chose Saturday, April 17, 1965, for the event. Most undoubtedly calculated that more students and workaday adults would show up on a weekend, but SDS was thereby repudiating the tactics first deployed by the generation of antiwar activists who, in the 1930s, had tried to shut down Brooklyn College, Columbia, the Seven Sisters, and the rest of the Ivy League. Those Depression-era student peace strikes were invariably held when weekday classes were still in session, much to the annoyance of college and university administrators, who often redbaited and expelled the ringleaders.

In the 1960s, however, we had antiwar marches, not student strikes. Almost regardless of who organized them — SDS, Trotskyists, pacifists, and by the end of the decade, liberal Democrats — they were held on a Saturday. Even the radical March on the Pentagon, designed to stop the war planners, came on a Saturday and Sunday in the fall of 1967.

In these marches, the main idea was to bear witness to the immorality of the war, to recruit new layers of society to the cause, and to make a political statement that would encourage congressional Democrats to defund the war while at the same time demonstrating the political cost of the conflict to pro-war conservatives.

There were exceptions to this strategy, as with the 1967 Stop the Draft Week effort in Oakland, which sought to shut down the army induction center there and the first big “moratorium against the war” in October 1969, a liberal-led effort designed to end business as usual for a day. Six months later came a genuine student strike, bigger than anything in the 1930s, when in the wake of a National Guard shooting at Kent State, which killed four protesters, millions of students forced the closure of more than four hundred colleges and universities, sometimes for the remainder of the school year.

But after this late 1960s burst of “shut-it-down” radicalism, the big American protests reverted to the model SDS had first established in 1965. Giant demonstrations, including the 1982 nuclear freeze march in New York City and the worldwide protests against the impending invasion of Iraq early in 2003, were held on Saturdays. Likewise marches defending women’s rights and those seeking full equality for gays and lesbians.

Even labor conformed to the pattern. When the AFL-CIO brought hundreds of thousands of members to Washington, in 1981 and 1991, for Solidarity Day rallies, they chose a summer Saturday for the two National Mall assemblies.

Indeed, for aging leftists, the periodic trek to the nation’s capital had begun to take on a ritualistic flavor. They were morally compelling and politically necessary, but they seemed to leave but a light impress on the social politics of the day.

The great exception came on May Day 2006, a Wednesday, when hundreds of thousands of people, mainly Latino, stopped work and took to the streets in a hugely successful series of marches in Los Angeles, Chicago, Dallas, Washington, and scores of smaller cities. They were seeking to forestall congressional passage of a repressive immigration bill, whose chief sponsor was Wisconsin Republican Congressman Jim Sensenbrenner.

This first Day Without Immigrants was not without controversy. Even within the Latino community, many thought this weekday protest amounted to a “punitive boycott” that would turn managers against workers, penalize thousands of low-wage Latinos, generate a political backlash against those pushing for immigration reform, and discredit their movement by linking it to radical labor and antiwar groups.

But the protests proved a stupendous success.

Latino pride and power took a giant leap forward. Thousands of workplaces shut down, and even some of the most viciously exploitative employers of Latino labor, like Perdue, Cargill, and Tyson Foods, closed their factories so as to avoid an open conflict with an energized and determined workforce. Immigrant truckers at the ports of Los Angeles and Long Beach demonstrated their strategic power by stopped the flow of thousands of containers worth billions of dollars.

This show of force paid off: within a month the Senate rejected the Sensenbrenner Bill, and in November the Democrats captured control of both legislative chambers, a prologue to Barack Obama’s presidential victory two years later.

With two strikes planned in the next few weeks, the stakes are even higher today. March 8, International Women’s Day, is shaping up as a day when women withdraw their labor from both home and work to resist the misogynist Trump agenda, while support from labor and immigrant quarters continues to build for a massive work stoppage and set of demonstrations on May 1, the historic marker that both medieval peasants and modern proletarians have celebrated as a springtime day of joy, solidarity, and liberation.

Both of these events are scheduled for weekdays, and yet there is still confusion about the purpose, impact, and possibility inherent in a set of political protests designed to simultaneously upend hierarchy and decorum in both the world of work and the public sphere.

Writing in Elle, Sady Doyle argues, in effect, for more Saturday-like demonstrations, because an actual work stoppage will expose vulnerable waitresses, maids, home health care workers, and other women at the bottom of the labor market to employer retaliation and loss of income. Meanwhile, women “with a comfortable office job may be able to ‘strike’ simply by taking paid time off and feel confident that her job will be there when the strike is over.”

Doyle summons history to her side, noting that the famous 1970 Women’s Strike for Equality, a march down Fifth Avenue, began at 5 PM because organizers knew that many female office workers in New York would not be able to get the day off.

But this is an entirely defeatist outlook, which misses the potential for solidarity and power, and yes, even for collaboration in this hour of crisis, as people from across the economic and social spectrum face a xenophobic assault on our civil liberties, voting rights, health care, freedom of the press, and the physical and psychological security of millions of American workers whose documentation or skin color has brought them under governmental suspicion.

A strike — not calling in sick, not taking paid time off, but an actual work stoppage — will not only demonstrate a sense of inclusive solidarity but will have the potential to put enterprises and institutions that employ a cosmopolitan, multicultural and multinational workforce — the Hollywood studios, Silicon Valley, higher education, hospitals and clinics, ports and warehouses, municipal government, and even the world of fast food and retail trade — in at least symbolic opposition to the Trump regime.

It will demonstrate the meaning of solidarity to millions entirely unfamiliar with unions or any other form of collective action and make clear that employees themselves can have a loud and independent voice. Such a movement will demonstrate once again that work and politics are indistinguishable and inseparable.