Study this map very carefully. Then look at any definition for gerrymandering.
This is now happening in Texas, proposed legislative districts for the next decade!
If you go to the Texas District Viewer and look for PlanH283 you can see this map for the entire state, and in much more detail. On that same page you can download reports on each district for population profiles, incumbents, and election history. Here is a document formed from the population profiles report on the House Districts in Dallas County: