Analysis of dozens of publicly created redistricting plans shows that map-making technology can improve political representation and detect a gerrymander.
n 2012, President Obama won the vote in Ohio by three percentage points, while Republicans held a 13-to-5 majority in Ohio’s delegation to the U.S. House. After redistricting in 2013, Republicans held 12 of Ohio’s House seats while Democrats held four. As is typical in these races, few were competitive; the average margin of victory was 32 points. Is this simply a result of demography, the need to create a majority-minority district, and the constraints traditional redistricting principles impose on election lines—or did the legislature intend to create a gerrymander?