Katz is part of a group of political scientists considered among the nation’s foremost experts on redistricting — developing a standard for evaluating the partisan bias of maps known as “partisan symmetry” which has been used for years by scientists and the U.S. Supreme Court to decide whether states were intentionally tilting electoral playing fields to help political parties or incumbents.

The method involves determining how an increase in voter-share translates into an increase in seats in a legislative body like Congress or a state legislature. With a perfectly neutral map, either Republicans or Democrats would gain the same number of seats on average for a given increase in the share of voters they turned out. Seats drawn with partisan intent would disproportionately boost the number of seats for one party over the other.

In Florida’s case, the plaintiffs in the lawsuit hired Katz at $500 an hour to analyze the re-drawn congressional maps. Katz concluded they were the most biased he had ever examined — easily twice as pro-Republican-leaning as Texas maps drawn by the chair of that state’s Republican Party.

More: Scientists: Florida’s Congressional Map Is ‘Partisan Gerrymander’ - Orlando Sentinel