It’s eight months before San Francisco’s mayoral election, with the eventual winner already in the field. While a candidate identified with the city’s political Left still may emerge, the current frontrunners are Board of Supervisors President David Chiu, City Attorney Dennis Herrera, and State Senator Leland Yee. Former Supervisors Bevan Dufty and Michela Alioto-Pier and Assessor Phil Ting will shape the outcome due to ranked choice voting, but none have reached the top tier. This is the first time since 1975 where there is no clear favorite in the Mayor’s race, but keep in mind that Jack Molinari in 1987 and Art Agnos in 1991 were heavy favorites in March and both lost. Here’s my assessment of the major upsides and challenges affecting the three current leading contenders.