Both Democrats and Republicans in the U.S. will claim that their opponents are the worse perpetrators when it comes to gerrymandering. Sam Wang and his team at Princeton University took a look at the data and graded states for their congressional and legislative redistricting. Here's his blogpost explaining the method, plus, at the second link, the results. "From this systematic comparison across every state, we learned that there is a very particular way that districting can be fair: take the power away from legislators."
