Chicago voters will decide the nation’s biggest mayoral race of 2023 in barely a week, and progressive Brandon Johnson is surging—thanks in part to a string of endorsements that have helped the former teacher and union activist close the gap with front-runner Paul Vallas.

Vallas, a former CEO of the Chicago Public Schools, has run to the right in the mayoral race. Relying heavily on Republican-style law-and-order rhetoric, he’s attracted significant financial support from business interests and Republican donors. That served Vallas well in the February 28 primary, when he finished first with almost 33 percent of the vote. Johnson, a Cook County commissioner, split the progressive and liberal vote with a number of other candidates, including ousted Mayor Lori Lightfoot and US Representative Jesus “Chuy” Garcia (D-Ill.), and finished in second with just under 22 percent.

That result put Johnson and Vallas in an April 4 runoff. Vallas began with the advantage of high name recognition and a hefty campaign budget, but the post-primary season has seen Johnson catch up.

A survey conducted last weekby the Chicago-based Victory Research polling group put Vallas at 46 percent to 44 percent for Johnson. The evidence of a rapidly tightening race comes as Johnson has received critical endorsements from Garcia and the Rev. Jesse Jackson. Johnson’s camp thinks that the backing from two icons of Chicago’s Latino and Black communities, respectively, will play a critical role in building the new “rainbow coalition” that Johnson, who is Black, needs to mobilize in order to beat Vallas, whose strongest support comes from predominantly white wards on the city’s northwest and southwest sides. (Vallas has secured the support of another Chicago power player, former representative Bobby Rush, as well as Illinois’s senior senator, Dick Durbin.)

Endorsements matter in Chicago, a big city where candidates win by piecing together multiracial and multiethnic coalitions and by mobilizing their base voters with intensive campaigning at the doorstep in diverse neighborhoods. The Vallas and Johnson campaigns well understand this reality. Both candidates are closely identified with the programs of key unions that have backed them. Fraternal Order of Police Chicago Lodge #7 is all in for Vallas, as is the historically conservative Chicago Tribune. The powerful Chicago Teachers Union (CTU) has provided volunteers and substantial financial support for Johnson, as have the American Federation of Teachers, several Service Employees International Union locals, and the Illinois Nurses Association. The United Working Families organization, the Sierra Club’s Illinois Chapter, and LGBTQ+ rights group Equality Illinois are also backing the county commissioner.

Johnson has been a member and organizer with the CTU in the past, so its enthusiastic support is no great surprise—especially since it has long been at odds with Vallas. But as the campaign intensifies, Johnson is having considerable success in identifying himself as the more reliably Democratic contender in an overwhelmingly Democratic city. There are no party lines on the ballot in the officially nonpartisan runoff election, and both candidates identify as Democrats. But Vallas has a long history of aligning with conservative causes and figures, and once announced, “I’m more of a Republican than a Democrat.”

Getting an endorsement from Garcia, who mounted a strong challenge to former mayor Rahm Emanuel in 2015 and came to national prominence as a top backer of Senator Bernie Sanders’s presidential bids, is seen as particularly vital for Johnson. Six Latino wards backed the congressman in the primary, and they are up for grabs on April 4. Jackson, a two-time presidential contender who has been a prominent figure in Illinois politics for more than 50 years, is expected to help Johnson mobilize support among Black voters, whose support was split among several contenders in the primary.

According to the Victory Research poll, Johnson now leads among Black voters by a striking 73.6 percent to 16.1 percent margin. Vallas retains the lead among white voters 71.7 percent to 21.9 percent. But Johnson is working to improve his numbers with white liberal voters by distinguishing himself as the candidate who is more committed to economic, social, and racial justice, and more loyal to the Democratic Party. In one of the first debates of the runoff campaign, Johnson ripped Vallas for accepting support from billionaires who frequently back GOP contenders and for appearing on a podcast with a host who attacked critical race theory. (In that interview, Vallas seemed to suggest that school curriculums that emphasize the teaching of Black history and culture are “giving people an excuse for bad behavior,” and fretted that “we seem to be preoccupied, too much focusing on those things rather than on focusing on our core curriculum, our standards suffer.”)

“I’m proud to have a multicultural, multigenerational campaign. Black, brown, Asian, young, old. We’ve built a coalition across this city,” Johnson said in the debate. “But Paul Vallas has made it about race. He has. The young people in the city of Chicago deserve Black history. He’s the one who said that should not happen.”

Johnson has also benefited from endorsements by Democratic members of Congress from Illinois, including Representatives Jonathan Jackson, Delia Ramirez, Danny Davis, Jan Schakowsky, and Garcia. And he’s attracted notable support from national progressives, including Senators Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.). “Commissioner Brandon Johnson has been a champion for working families in Chicago,” declared Sanders, who will appear in Chicago Thursday for a major rally with Johnson. “He is not afraid to stand up for strong unions and make big corporations and the rich pay their fair share to invest.” Warren said, “Brandon Johnson is a former public school teacher with a bold, forward-looking, progressive plan to move Chicago forward—and the experience to make it happen.”

Prominent House Democrats from other states, such as Representatives Jim Clyburn of South Carolina, Jamaal Bowman of New York, Ayanna Pressley of Massachusetts, Brendan Boyle of Pennsylvania, and Troy Carter of Louisiana, have lent Johnson their backing as well. Boyle and Carter even cut an ad for Johnson, in which they recalled Vallas’s controversial management of schools in Philadelphia and New Orleans. Discussing school closings and deficits that were issues during Vallas’s tenures leading school districts in their cities—as well as Vallas’s support for local Republicans—the House members warned, “Paul Vallas is bad for Chicago. How do we know? Because he was bad for Philadelphia and he was bad for New Orleans. We hope Chicago doesn’t make the same mistake.”