In April 1955 I arrived in Chicago just in time to see the first Mayor Daley elected for the first time. Twenty-two years of residency provided a practical course to those years of study concerning American government. Mayor Daley was dead before I left but his name remains on the Square at City Hall. He was famous for instructing Cook County, not to mention Springfield, how to run things. Perhaps hizzoner was most famous during the 1960 election where Illinois decided the election of two Senators, veterans both, for the highest office in the land. Wiki at one time described Hillary Clinton, a resident of a northern suburb and a youthful adherent of Barry Goldwater, as being asked by the Republicans to help with a recount of voters in the South Side. Richard Nixon declined to challenge John Kennedy. It was generally conceded that the mayor won.
After I left the city which worked--but wasn't during Rust Belt days--I kept up with Harold Washington's mayoral record, cut short by death shortly after re-election to a second term. Barack Obama describes a scene in his first book where the mayor, African-American, made a trip to Altgeld Gardens festivities where he, our current president, was an organizer. We know Obama's trajectory, including later experiences as a law professor and lawmaker in Springfield. I view his second book mostly as an application for the top job.
Clout depends upon who has the top job. It is shored up with willing accomplices ready to climb ladders of success. For a case study, look at Blago. He aimed at the mayor's job from a governorship, and flopped. Former Illinois governors have been known to leave under clouds and sidetracked to judgeships only to go straight to jail.
All of this brings up questions of a second term of office for Obama. Go figure! Some will look at pronunciation and long sentences and deny that the current man in the Oval Office does not have clout. If lucky, I'll live to see how that works out.