Chicago simmers over school closings. Is that bad for Mayor Emanuel?

Chicago’s controversial decision to close 50 public schools was challenged by a third lawsuit Wednesday, inflaming a public relations war between City Hall and the teachers union that polls say is being waged at a time that Mayor Rahm Emanuel is more vulnerable politically.

Two federal lawsuits were filed last week by parents saying that the closings violate the civil rights of special needs children and those living in poorer, marginalized neighborhoods...