This is fascinating:
There’s a lot of complaining about gerrymandering, but what should districts look like? We went back to the drawing board and drew a set of alternative congressional maps for the entire country. Each map has a different goal: One is designed to encourage competitive elections, for example, and another to maximize the number of majority-minority districts. See how changes to district boundaries could radically alter the partisan and racial makeup of the U.S. House — without a single voter moving or switching parties
The entire FiveThirtyEight gerrymandering project is worth exploring . . .