Nearly four weeks since the end of the first teachers strike in 25 years, and 17 months after being recruited from Rochester, N.Y., by Chicago Mayor Rahm Emanuel in May 2011, Chicago Public Schools CEO Jean-Claude Brizard is stepping down, reports the Christian Science Monitor. Mr. Brizard’s resignation, announced in a statement, highlights the difficulties school administrators face in the Chicago system, where school officials are more directly answerable to City Hall and vulnerable to the political pressures on the mayor…