This appeared in yesterday's NY Times: "Race, Politics and Drawing Maps: The Supreme Court Hears an Alabama Case on the Voting Rights Act"
http://www.nytimes.com/2014/11/14/opinion/the-supreme-court-hears-an-alabama-case-on-the-voting-rights-act.html

A more general discussion appeared a few years ago in The Atlantic: "The League of Dangerous Mapmakers"
http://www.theatlantic.com/magazine/archive/2012/10/the-league-of/309084/

This is an old subject: http://press.uchicago.edu/ucp/books/book/chicago/B/bo3645208.html .

         Joel Kovarsky