Union organizer and Cook County Commissioner Brandon Johnson was narrowly elected mayor of Chicago on Tuesday, defeating moderate Democrat Paul Vallas, the city's former budget director and Chicago Public School's CEO. 

Johnson, who was backed by the Chicago Teachers Union and a coalition of progressive activists, was the second-place finisher in the February general election, which went to a runoff because neither candidate earned a majority of the vote. Though he trailed Vallas by nearly 70,000 votes in the first round, the 46-year-old underdog claimed an upset victory – winning the race with 51.4% of the vote to Vallas' 48.6%. 

In his victory speech, Johnson vowed to "take this bold, progressive movement around these United States of America." 

"Tonight is a gateway to a new future for our city," Johnson said. "A city where you can thrive regardless of who you love or how much money you have in your bank account. A city that’s truly safer for everyone by investing in what actually works to prevent crime. And that means youth employment, mental health centers, ensuring that law enforcement has the resources to solve and prevent crime."

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Union organizer and Cook County Commissioner Brandon Johnson

Brandon Johnson speaks after being projected winner of the mayoral election on April 4, 2023, in Chicago. (Alex Wroblewski/Getty Images)

A lifelong progressive, Johnson was born in Elgin, Illinois, and is one of 10 siblings. His parents were pastors and foster parents who raised him "on a foundation of hard work, faith and service," according to his campaign website.

He began his career as a public school social studies teacher and went on to become an organizer with the Chicago Teachers Union, one of the most powerful political forces in the Windy City. He helped organize the 2012 Chicago teachers strike and led field campaigns for the 2015 mayoral runoff election, according to Politico. CTU President Stacy Davis Gates addressed the crowd on stage at his election night victory party. 

"His movement of community, love and justice is going to transform not just the city of Chicago, but the United States of America," Gates said. 

Johnson became a Cook County commissioner in 2018, ousting an incumbent with the backing of labor unions and various progressive groups, including Our Revolution – a spinoff of Vermont Sen. Bernie Sanders' 2016 presidential campaign. He earned Sanders' endorsement in the 2023 mayoral election. 

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Supporters gather at Brandon Johnson's victory party in Chicago

Supporters celebrate after it was reported that Brandon Johnson had taken a lead against Paul Vallas in the mayoral runoff election Tuesday, April 4, 2023, at the Marriott Marquis hotel in Chicago. (Armando L. Sanchez/Chicago Tribune/Tribune News Service via Getty Images)

As Cook County commissioner, Johnson advocated for and successfully enacted a "Just Housing" ordinance that limited the ability of landlords to inquire about a potential tenant's criminal history. He also drafted a symbolic resolution that called for diverting money away from police departments as the "defund the police" movement gained national prominence in 2020 after the police murder of George Floyd, a Black man. 

Johnson continued to do legislative work for the CTU while in office, earing a six-figure salary, according to Politico's Illinois Playbook. He was speculated as a potential candidate for mayor as early as 2019.

Johnson's eventual mayoral campaign was announced in October 2022 with endorsements from the CTU, United Working Families, and local and national left-wing activist groups. In conversations with voters, he talked about his experience as a public school teacher, growing up in poverty and living with gun violence in the city's West Side. 

"I've had to shield my children from bullets that fly right outside our front door," Johnson said Tuesday night. 

He promised to address crises facing Chicago ranging from crime, the lack of affordable housing and the city's $127.9 million budget shortfall by investing more money in community programs and mental health resources. 

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Progressive mayoral candidate Brandon Johnson and Bernie Sanders

Progressive mayoral candidate Brandon Johnson and Sen. Bernie Sanders raise their hands to a crowd of supporters at Johnson's rally at the UIC Forum March 30, 2023, in Chicago. (Jim Vondruska/Getty Images)

With crime a major issue in the campaign, Johnson faced attacks over his support for the "defund the police" movement, particularly 2020 comments he made stating that cutting police budgets was an "actual, real political goal." He distanced himself from those comments in the late stages of the mayoral race, insisting, "I said it was a political goal. I never said it was mine." 

The mayor-elect has said he will not reduce the Chicago Police Department's budget, however, he also has said hiring more police officers or increasing funding will not solve the city's crime problems. He has committed to promoting 200 detectives from rank-and-file officers and has argued for increased city spending on mental health care, schools and affordable housing to address the root causes of crime. 

He has also supported having social workers and EMTs respond to some 911 calls instead of armed police officers.

Johnson's priorities as mayor, according to his campaign website, range from "public safety and police reform" and "environmental justice" to "gender equity" and "education." 

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Brandon Johnson/Paul Vallas

Brandon Johnson defeated Paul Vallas and will replace outgoing Mayor Lori Lightfoot. (Chicago Tribune | Getty Images)

Johnson, according to the website, is "passionate about making sure that every student in Chicago – regardless of their race, income or zip code – receives a fully resourced, supportive, safe and healthy learning environment."

Additionally, Johnson says on his campaign website that he aims to "work closely with the Community Commission for Public Safety and Accountability to hold police accountable and evaluate the goals and performance of the CPD, the Civilian Office of Police Accountability and the Police Board."

Johnson will be the fourth Black mayor in Chicago history. In his victory speech, he thanked God and his wife, Stacy, and their three children for their support. He also referenced the civil rights work of Dr. Martin Luther King Jr., describing the movement that is sending him to City Hall as a continuation of that legacy. 

"It was right here in the city of Chicago that Martin Luther King, Jr. organized for justice, dreaming that one day that the civil rights movement and the labor rights movement will come together," Johnson said. 

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"The civil rights movement and the labor rights movement has finally collided." 

Fox News' Kyle Morris contributed to this report.