According to the Associated Press, the map in Pennsylvania resulted in an additional three seats for Republicans than they would have won otherwise. The only state with a larger number of extra seats won was Texas.
The AP used a method of determining how well each party turns votes into victory in districts called the “efficiency gap.”
Franklin & Marshall College political scientist G. Terry Madonna called Pennsylvania’s current map “the worst gerrymander in modern Pennsylvania history.”
The AP looked at all 435 Congressional and 4,700 state legislative elections from 2016, and found Republicans won as many as 20 extra congressional seats nationally.
Pennsylvania’s map is facing a court challenge from the League of Women Voters and voters from all 18 of Pennsylvania’s Congressional districts asking for the current map to be thrown out and a new map to be drawn.