Education policy quickly emerged as a central issue in the contest between Johnson and Vallas, which the progressive won with just over 51% of the vote.
A former public school teacher and longtime union organizer, Johnson vowed to prioritize investments in public education and oppose charter expansions—an agenda that couldn't have contrasted more sharply with that of Vallas, the former CEO of Chicago Public Schools and an ardent supporter of school privatization.
Vallas, whose campaign was backed by Republican donors and business interests, aggressively pursued school privatization schemes during his tenure as the head of school districts in Chicago, New Orleans, and Philadelphia—a record that Johnson's campaign spotlighted in an ad that aired this week as well as in debates ahead of Tuesday's vote.
"My opponent talks about school closures," Johnson said during one debate. "Well, he set up the market for schools to be closed. He got so good at it, he went around the country doing it."
Maurice Mitchell, national director of the Working Families Party, said in a statement late Tuesday that the Chicago runoff marks "a win for the history books."
"Brandon Johnson just defeated a deluge of far-right money and misinformation thanks to people power and his positive vision for a safe and thriving Chicago," Mitchell added. "Now comes the hard work of building a Chicago for the many, with strong schools, good jobs, and safe communities," Mitchell added. "We look forward to working with Brandon and the new class of Working Families alder members to reopen mental health clinics, pass universal childcare, and implement a local Green New Deal."
In contrast to Vallas, whose campaign was also backed by a super PAC with close ties to former Education Secretary Betsy DeVos, the bulk of Johnson's support came from unions such as the American Federation of Teachers (AFT) and the Chicago Teachers Union (CTU).
"Make no mistake about it," Johnson said in his victory speech, "Chicago is a union town."
Stacy Davis Gates, president of the CTU, said in a statement that "today, Chicago has spoken."
"Chicago has said yes to hope; yes to investment in people; yes to housing the unhoused, and yes to supporting young people with fully-funded schools," said Gates. "It is a new day in our city."
AFT President Randi Weingarten called Johnson's win "a transformational moment" that "sends a message that efforts to exploit anxiety will not work in the face of a multiracial, multiethnic, multigenerational working-class movement standing together as one."
Johnson's upset win Tuesday capped off a remarkable rise for a progressive lawmaker who was polling at just over 3% in December. At that time, according to one survey, Vallas was polling at 19%.
In January, Chicago's outgoing mayor, Lori Lightfoot, brushed aside the CTU's endorsement of Johnson, saying: "Brandon Johnson isn't going to be the mayor of this city."
During his remarks Tuesday night, Johnson gave a nod toward those who dismissed his chances.
"They said this would never happen," he told a crowd of supporters. "If they didn't know, now they know."
