Check out this great redistricting game online. Normally I won’t talk up online games, but this is a map game. Ah, the power of the cartographer!
The object is to redraw the voting districts for imaginary places based on certain criteria and public reaction so that you can get an idea how redistricting can affect the election process. The most obvious abuse of this is gerrymandering, or the process or redrawing a congressional district so that your candidate or party is guaranteed to win every time.
Hat tip to CatholicGuaze.