Here's an article about redistricting :
MATHEMATICAL ASPECTS OF GERRYMANDERING (p. 3) by Paul Kehle.
...some of the interesting questions and issues that arise, capture student attention in ways that, while thoroughly mathematical, have little to do with gerrymandering. The topic is a rich and generative one completely apart from the initial thorny issue of deciding when a district map has gone beyond what is considered fair. In the explorations below and in working with students there are no boundaries to the questions worth exploring; and you and your students will likely come up with many not considered here, some even lead to questions at the frontier of mathematics and computing research.
...In the simplified geographically square state represented by Vote Scenario 5a, there are 25 blocks, and each block gets one vote. The constitutionally required ratio of representatives to blocks in this country is 1:5 and so the 25 blocks must be partitioned into five congressional districts of 5 blocks each. In addition to other simplifications we make in this model, we assume there are only two political parties, the Green Party and the Purple Party. In the map, green and purple indicate how each block tends to vote. Another simplification in our model is a rule that we impose on the shape of the districts. To be a legal district, each block in the district must share at least one edge border with another block belonging to the same district. Even in such a simple model, students can gain familiarity with the general principles underlying the model and with the heart of the gerrymandering issue by calculating how many districts each party wins in District Map #1 and District Map #2. To win a district, we will assume that the party needs to win at least three of its five blocks.
