**Alexi Giannoulias leads trader pricing in the 2027 Chicago mayoral race at 57% amid a crowded field that includes incumbent Brandon Johnson at 12% and Susana Mendoza at 12.5%.** Giannoulias announced his candidacy in early August with roughly $22 million in cash on hand, major trade-union backing, and endorsements from several aldermen, positioning him as a frontrunner focused on public safety hiring, housing, and fiscal management. Johnson’s late-September reelection launch followed polls showing his approval near 23% and limited enthusiasm for a second term, while Mendoza and other declared candidates such as Mike Quigley and Maria Pappas trail in both fundraising and early surveys. The February 23 primary and potential April runoff keep the outcome open, as petition challenges, turnout among core coalitions, and further spending could still shift support before voters decide.