AP: Partisan map-making advantage grew in Ohio

COLUMBUS (AP) — A political map-making process controlled by Ohio Republicans proved nearly impenetrable to Democrats' efforts during the 2018 elections, an Associated Press analysis has found, delivering results that allowed the GOP to retain sizable majorities even in the face of an upswing in Democratic votes.

The analysis found that Ohio Republicans won at least three more U.S. House seats and seven more state House seats than would have been expected based on the average share of the votes that Republicans received. Both gaps grew compared with 2016, when the same analysis showed Republicans winning nearly two more U.S. House seats and five more Ohio House seats than expected based on their share of the votes.

The AP used a mathematical formula for calculating partisan advantages that is designed to flag potential cases of political gerrymandering, a practice where the party in power alters voting districts to its advantage in federal and state legislative races. The 2018 analysis again placed Ohio's "efficiency gap" near the top for both state and federal legislative races.

The 2018 analysis found Republicans won 52 percent of the votes in Ohio House races yet 62 percent of the seats. Republican candidates for Ohio's U.S. House seats won 52 percent of the votes but 75 percent of the state's 16 congressional seats. Republican support was down nearly 4 percentage points from 2016 for state House races and almost 6 percentage points in U.S. House races, the analysis showed.

The finding comes as a federal court panel weighs its decision in a lawsuit by Democrats alleging that unconstitutional partisan gerrymandering has disadvantaged Democratic voters in Ohio congressional districts. After arguments earlier this month, the panel has not yet ruled. Ohio's current map was enacted in 2011 by a Republican governor and Republican-led Legislature.

Since then, Ohioans have voted to change the redistricting process and make it less partisan.