Chicago, Ill.—Anyone who doubts the power of organized labor to reshape the world should look to the Chicago Teachers Union (CTU) and its allies’ electing one of their own as mayor of the third-largest city in America last night. Brandon Johnson, a black 47-year-old Cook County commissioner and former CTU member and staffer, shocked this city by winning its mayoral runoff, besting former Chicago Public Schools (CPS) CEO Paul Vallas by about 16,000 votes as of late last night, after running an unabashedly progressive campaign calling for expanding social services and new taxes on the rich. This despite Vallas’s austerity- and crime-obsessed campaign (funded principally by the wealthy) outspending Johnson’s campaign (funded principally by unions) nearly two to one.

Speaking on the 55th anniversary of the Rev. Martin Luther King Jr.’s assassination, Johnson told an ebullient crowd during his victory speech that King had dreamt “that one day, the civil rights movement and the labor rights movement will come together. Well, Rev. Martin Luther King Jr., the civil rights movement and the labor rights movement [have] finally collided.”

But those who have paid attention to the CTU’s audacious program in recent years probably aren’t shocked. The union is the boldest local union in America and has assembled a broad coalition of community groups, progressive unions, and leftist elected officials around a shared agenda of fighting the austerity, poverty, racism, and gentrification that have reshaped Chicago politics in the past decade and a half.

The union’s program is a result of the election in 2010 of a militant, reform-minded teachers union leadership, the Caucus of Rank-and-File Educators, that has continually advanced demands related to the struggles of the city’s poor and working class, gone on strike repeatedly, and carried out a systematic and successful plan to elect pro-worker candidates at the local, county, state, and federal levels through the political organization United Working Families. And despite the constant characterization of the CTU as “divisive” in mainstream media accounts, the union consistently wins over huge swaths of the city to its agenda. The CTU has repeatedly undertaken difficult campaigns and won; Johnson’s win is only its latest.

Johnson, a former middle school teacher in the Cabrini Green housing projects who spoke frequently of the struggles of his impoverished students, ran on a platform of reducing economic inequality, ending poverty, defending workers’ rights, strengthening the public sector, and opposing austerity. He pitched taxing the rich as central to an anti-violence strategy, proposing $800 million in new taxes to pay for $1 billion in new spending on jobs, public education, public transit, affordable housing, health care, and mental health services.

He came in second in the election’s first round, defeating incumbent Mayor Lori Lightfoot, who netted a pitiful 17 percent after struggling with crime and battles with the CTU. (Just a few weeks earlier, Mayor Lightfoot said of the CTU, “They’ve endorsed Brandon Johnson. God bless. Brandon Johnson isn’t going to be the mayor of this city.”)

Vallas, who was the top vote-getter in the first round, put crime at the center of his campaign, reflecting many Chicagoans’ fears over rising crime rates (63 percent of Chicagoans recently told one pollster they don’t feel safe) and attacking Johnson for previously embracing the rhetoric of “defund the police,” though Johnson now rejects the phrase. But the attacks didn’t work.

Johnson said he would not cut “one penny” from the police budget but pledged to invest in social services and new economic opportunities to get at the “root causes” of crime while “deal[ing] with the immediate challenge of public safety in the city of Chicago.” And he spoke repeatedly about the “Treatment, Not Trauma” ordinance that would send unarmed mental health professionals and paramedics rather than armed police to intervene with people facing mental health crises. Johnson did not shy away from a message that more police and more guns could not fix the city’s public safety woes, and voters did not punish him for it.

A refusal to back away from progressive rhetoric helps explain why Johnson’s campaign had the unmistakable feel of a grassroots social movement. A rally with Senator Bernie Sanders last week drew 4,000. The gentrifying neighborhood of Logan Square on the city’s northwest side—which turned out huge numbers for Johnson, thanks in large part to its independent political organization United Neighbors of the 35th Ward and socialist city council member Carlos Rosa—saw anti-Vallas and pro-Johnson fliers and posters plastered everywhere, many of which were not officially produced by the campaign. Bootleg T-shirts designed and made by supporters were easy to come by. And Johnson’s victory party was populated by close to 1,000 union members, staffers, and activists whose energy crackled.

The union now leaves a trail of defeated enemies in its wake: Vallas, the architect of attacks on public schools in Chicago and around the country who promised a mayoralty of law and order, privatization, and budget cuts; Lightfoot, the hapless one-term mayor who went up against the CTU in a 2019 strike and over school reopenings during the pandemic; and, most famously, Rahm Emanuel, whose mayoralty came to an unexpected end after he repeatedly demonized the CTU, lost to the union during the 2012 strike, and shuttered 49 schools in working-class and poor neighborhoods shortly thereafter; several CPS CEOs and heads of charter school chains, who took on the union only to later resign or be prosecuted for corruption. It has also ended the careers of numerous city council members, county commissioners, and other elected officials, replacing them with pro-union UWF candidates.

Johnson’s election wasn’t easy. But now things get truly tough. Traps and snares await him at every turn. The head of the Fraternal Order of Police in Chicago has threatened open revolt of police officers and “blood in the streets” under a Johnson mayoralty. Corporations may flee the city, particularly if he pursues the kind of aggressive taxation of the rich that he ran on. More conservative city council members may engage in procedural chicanery to try to block his agenda, in the vein of the “council wars” under Mayor Harold Washington. And his public safety approach will almost certainly be immediately put to the test in a city where gun violence is a tragically common occurrence, with the whole world—including the many Democrats who lined up against him in the race—ready to pounce on any perceived misstep. Not to mention the normal range of developments that can sink a mayor: corruption, botched responses to natural disasters, scandals of all kinds.

Johnson will be walking a tightrope in office. But he has an advantage in the city’s labor movement. The CTU and its allies rightly see Johnson as one of their own; their members will need to mobilize throughout his mayoralty, both to protect him from attacks and to ensure he does not abandon his progressive goals in the face of corporate intransigence. It is that movement, made up of workers who have learned in recent years to act confidently and uncompromisingly on their own behalf alongside parents and other community members to advance a vision of a city and world without poverty, that has propelled Johnson from an underfunded middle school classroom to strike picket lines to mayor-elect of an American metropolis. He won’t be able to fulfill his election’s promise without those workers’ help.