That assertion taps into the ire of TIF critics who say the special taxing districts siphon of hundreds of millions of dollars a year that otherwise would go to local taxing districts, about half of which would have gone to CPS. That's the point that puts Rauner on the same page as the Chicago Teachers Union, which has often likened the city's TIF system to a slush fund that serves as a piggy bank for the mayor and aldermen to the detriment of local schools.