Video: The WTTW News Spotlight Politics team breaks down the biggest headlines of the day with special guest Angela Rozas O'Toole, senior editor of government and politics at WBEZ Chicago. (Produced by Alexandra Silets)

The Service Employees International Union Local 1 became the latest union to endorse Brandon Johnson in the Chicago mayor’s race on Wednesday, as businessman Willie Wilson, who finished fifth in the first round of voting, backed Paul Vallas.

SEIU Local 1, which represents 45,000 janitors, security officers, airport workers, home care workers and window washers, is the first major labor organization to back a candidate for mayor after the Feb. 28 election.

SEIU Local 1 joins SEIU Healthcare Illinois, which has 90,000 members, and SEIU Local 73, which backed Johnson in November, after being neutral in the first round of voting. SEIU Local 73 counts 16,000 Chicago public sector workers among its membership.

“Brandon is an organizer, a teacher, a Cook County commissioner and a longtime community activist, and most importantly for me and my union, he is one of us,” said Genie Kastrup, president of SEIU Local.

The support of the three SEIU-affiliated unions, along with the 20,000-member Chicago Teachers Union, ensures that Johnson will have a motivated base of well-funded supporters to take on Vallas in the April 4 election.

Johnson also now has the backing of the Illinois chapter the Sierra Club, an environmental group, Equality Illinois, the state’s largest LGBTQ civil rights advocacy organization, along with Cook County Board President Toni Preckwinkle and U.S. Rep. Danny Davis.

Johnson will need the support of deep-pocketed labor unions to keep pace with Vallas, who reported $1.3 million in contributions to his campaign account just on Tuesday, less than a week after he lent his campaign $100,100, lifting the state-imposed caps on contributions.

Those contributions included $200,000 from Citadel Chief Operating Officer Gerald Beeson and Matthew Simon, the head of Ashler Capital for Citadel. Citadel founder and CEO Ken Griffin, who now lives in Florida, told Bloomberg that he hopes “Paul Vallas becomes the mayor of Chicago. I think he’s the best choice for the city.”

Griffin, a major Republican donor, worked to deny Democratic Gov. J.B. Pritzker a second term and spent $54 million to torpedo Pritzker’s effort to raise Illinois’ income tax for the state’s wealthiest residents.

Vallas also landed the endorsement of Wilson on Wednesday. Wilson and Vallas were the only candidates in the race not to run as progressives, and both courted the endorsement of the Fraternal Order of Police, Lodge 7, which represents Chicago’s rank-and-file officers.

Vallas consolidated conservative voters in Chicago by winning the endorsement of Chicago’s police union, while Wilson’s campaign faltered after he said that police officers should be able to chase those who flee and “hunt them down like a rabbit.”

Vallas said he was proud to have Wilson’s endorsement. Ald. Roderick Sawyer (6th Ward) also endorsed Vallas after finishing in ninth, and last, place.

Wilson said he endorsed Vallas in part because he would improve the Chicago Public Schools. There is no evidence to support Wilson’s statement on Wednesday that graduates of the Chicago Public Schools graduate without being able to read or write or “even tie their shoes up.”

Vallas said he would work to ensure all Chicago students get “quality educational opportunities regardless of their ZIP code, regardless of their income.”

Vallas supports efforts to expand charter schools as well as programs that use public funds to pay tuition.

Johnson is a paid organizer for the teachers’ union who was reelected to the Cook County Board of Commissioners in November.

Progressive groups in Chicago worked for nearly a year to lay the groundwork to defeat Lightfoot by uniting behind a single candidate. Those groups endorsed Johnson, but that effort ran aground after U.S. Rep. Jesús “Chuy” García launched his bid for Chicago mayor.

García, along with the largest labor union that backed him, the International Union of Operating Engineers Local 150, have yet to endorse in the runoff for Chicago mayor.

The second round of voting gives Johnson a chance to reassemble the coalition of progressive groups and labor organizations he had hoped would deny Mayor Lori Lightfoot a second term as part of the effort to defeat Vallas. The police union is the only labor organization to endorse Vallas.

Contact Heather Cherone:@HeatherCherone| (773) 569-1863 |[email protected]