Song likely protests the regime of mayor Richard Daley (1911-1976) who was as ruthless as they come. Even his own son would distance himself from his father's doings when he became mayor.
The radical left of the sixties who did have a legitimate gripe, the Vietnam War. Unlike the left of today who doesn't have a clear message. Maybe today's left wants a welfare state. Chicago Dem Convention riot Abbie Hoffman, Jerry Rubin, Tom Hayden, Bobby Seale etc., I think they have all passed.
For those wondering, the musicians are lead vocalist-guitarist-tambourinist-pianist-organist Graham Nash; backing vocalists Rita Coolidge, Vanetta Fields, Clydie King, Shirley Matthews, and Dorothy Morrison; bassist Chris Ethridge; and drummer John Barbata.