In 2016, a North Carolina legislator announced that his party would be redrawing the state’s congressional district map with a particular goal in mind: To elect “10 Republicans and three Democrats.” His reasoning for this? As he explained, he did “not believe it’s possible to draw a map with 11 Republicans and two Democrats.”

It was a blatant admission of gerrymandering in a state already known for creatively-drawn districts. But that might be about to change. A North Carolina mathematician has come up with a way to quantify just how rigged a map is. And now he’s taking his math to court, in a case that could end up redrawing district lines across the country.