When Chicago elected Harold Washington as its mayor in 1983, it was a transformational moment for not just the nation’s third-largest city but all America. Washington was the city’s first Black mayor. He was also a street-savvy political maverick who had broken with the city’s powerful Democratic machinery to beat incumbent Mayor Jane Byrne in a primary and then prevail in one of the most contentious general elections in the history of American urban politics. And he was a progressive who was willing to take on reactionary forces by building a multiethnic, multiracial rainbow coalition that challenged the conventional wisdom of American politics in an era of deep divisions and a narrow understanding of what was possible.

Now, 40 years after Washington’s historic win, a progressive has beaten an incumbent mayor in a Chicago primary and is headed for what will, once again, be a contentious general election. If that progressive, 46-year-old Cook County commissioner and Chicago Teachers Union organizer Brandon Johnson, prevails in the April 4 runoff election, it will be another transformational moment for the city and the country.

“Tonight is about building a Chicago that truly invests in our people,” Johnson told throngs of cheering supporters after his victory in Tuesday’s mayoral primary. “The most radical thing we can do as a city is to love the people of Chicago. Loving people and investing in people—that is the way my father raised me. The finances of this city belong to the people of the city. So, we’re gonna invest in the people of the city.”

That’s not just campaign rhetoric. Johnson has a plan to tax billionaires and multinational corporations—Chicago has plenty of both—with an eye toward raising $1 billion for schools, transportation, new housing, expansion of health care and mental health services, and ambitious jobs programs. He also wants to restructure the Chicago Police Department’s $1.94 billion budget to implement reforms that root out racism, reassign officers and make the department part of a comprehensive anti-violence initiative. Rejecting simplistic responses to crime issues that have been front-and-center in this year’s mayoral campaign, Johnson has bluntly declared that “spending more on policing per capita…has been a failure,” and explains, “Look, I get it. People are talking about policing as a strategy. But, keep in mind, that is the strategy that has led to the failures we are experiencing right now.”

This broader vision of how to combat not just crime but also the societal challenges that lead to violence is in stark contrast to the program offered by the candidate Johnson will face on April 4.

Just as Washington had to beat back the crudely divisive campaign of state Representative Bernard Epton in the 1983 general election, Johnson now has to defeat former Chicago Public Schools CEO Paul Vallas, who goes into the general election with money and a solid base in the same overwhelmingly white wards on Chicago’s northwest and far west sides that opposed Washington 40 years ago. Vallas has run an old-school “law and order” campaign, in which he has proposed to “take the handcuffs” off the police and welcomed the support of the local Fraternal Order of Police union. The police union’s leadership has a record of promoting a rigid “tough on crime” agenda—and of giving encouragement to Donald Trump’s extremism. Vallas, who has lost previous campaigns for mayor and governor of Illinois, has a history of adopting conservative positions on education and criminal justice issues, going so far as to once suggest—in 2009, shortly after the election of Chicago Democrat Barack Obama as president—that he was “more of a Republican than a Democrat.”

In this year’s officially nonpartisan mayoral race, all the top candidates identified as Democrats. But Vallas clearly ran to the right and, with financing from corporate interests, he had a good primary night—winning 33.8 percent of the vote for a first-place finish in a nine-candidate field. Johnson was second, with 20.3 percent. One-term mayor Lori Lightfoot, the first Black woman and the first out member of the LGBTQ+ community to lead the city, took 17.1 percent and was eliminated from the race. So, too, was progressive US Representative Jesús G. “Chuy” García, a supporter of Vermont Senator Bernie Sanders’s presidential bids, who got 13.7 percent, after a campaign in which Lightfoot spent heavily on attack ads that targeted García but did little to help the embattled mayor’s own prospects.

Vallas is being painted as the front-runner. But Johnson has a strong campaign operation and a plan. He’s backed by the politically savvy United Working Families organization, the Illinois affiliate of the national Working Families Party, as well as the powerful Chicago Teachers Union and Service Employees International Union locals that know how to do politics in Chicago. He’s also strongly supported by US Representative Delia Ramirez (D-Ill.) and some of the most dynamic members of the state legislature, the county commission, and the city council, including alderpersons Rossana Rodríguez-Sanchez and Carlos Ramirez-Rosa.

Johnson’s campaign brought him from the back of the field, as a relatively unknown candidate for citywide office, to a primary win by deploying thousands of activists in the city’s neighborhoods in January and February. They’ll keep right on going in March and April, and they’ll have plenty of room to grow their numbers by seeking support from Lightfoot and García supporters. Johnson was already reaching out to them on primary night. He also acknowledged that his insurgent campaign had caught a lot of political insiders by surprise, telling supporters, “A few months ago, they said they didn’t know who I was. Well, if you didn’t know, now you know!”

Rejecting Vallas’s attempts to reposition himself as a relatively mainstream Democrat in an overwhelmingly Democratic city, Johnson reminded the crowd that Vallas has courted and received support from right-wingers and corporate interests. “He switched parties when President Barack Obama became president of the United States. He went so far as to say he’s more of a Republican than anything else. He says he fundamentally opposes abortion,” declared Johnson. “These are direct quotes.”

In Chicago, a city that takes politics seriously, few punches are pulled. This will be a tough campaign, perhaps as tough as the 1983 race that swept Washington into office. But Johnson believes he can win, just as his legendary predecessor did.

Echoing Washington, Johnson says, “We have shifted the political dynamics in this city.”

We’ll know just how far on April 4.