For better or worse, Chicago seems likely to be home to more charter schools over the next few years. Critics suggest that there are already too many, that they disrupt neighborhood schools, and their performance is mixed. Race To The Top required that states get rid of charter caps in order to be eligible for funding.
This list (PDF) from NAPC suggests that, compared to many other cities with low-performing school systems, Chicago has relatively few charters. The top ten: 1. New Orleans 70% 2. Washington, D.C. 39% 3. Detroit 37% 4. Kansas City 35% 5. Flint, Mich. 32% 6. Gary, Ind. 30% 7. St. Louis 29% 8. Dayton, Ohio 27% 9. Youngstown, Ohio 24% 10. Albany, NY; Cleveland, Ohio ; Toledo, Ohio 23%
Then again, Los Angeles, New York City, and Miami aren't on the top ten list, either, and big foundations like Gates seem more focused on charter-district collaboration and shared approaches than on pure growth.