Alexi Giannoulias leads the 2027 Chicago mayoral field at 67% implied probability due to his commanding fundraising edge of roughly $22 million, trade union backing, and high statewide name recognition as Illinois secretary of state. He entered the race in August 2026 promising additional police hires and coalition-style governance, contrasting with incumbent Brandon Johnson’s 14% odds amid the mayor’s persistently low approval ratings, repeated City Council clashes, and stalled fiscal initiatives. Susana Mendoza follows at 9.5% with solid but more limited resources, while lower-polling contenders such as Kam Buckner, Maria Pappas, and George Cardenas face steeper paths in a crowded February 23 primary that likely heads to an April runoff. Recent veto disputes and Johnson’s September reelection announcement have reinforced trader views of Giannoulias as the primary alternative.