A previous efficiency gap analysis conducted by Simon Jackman, a former professor of political science and statistics at Stanford University, found that the Republican advantage was even higher in the 2012 and 2014 Missouri House elections. The Old Dominion's off-year elections often serve as a bellwether for national trends.
President Donald Trump is bemoaning what he calls "the level of hostility" that he says has stymied bipartisanship in Washington.
The AP also calculated efficiency gap scores for U.S. House elections, translating those into estimates of extra seats won because of partisan advantages.
Other districts - such as Beatty's, where 9 of every 10 voters favor Democrats - are virtually impossible for Republicans to win.
He'd like to see nonpartisan legislative staff draft initial maps and a supermajority consensus required by redistricting and reapportionment panels.
Republicans initially tried to redraw the lines to divide Maine's two congressional districts into an east-west configuration instead of north-south. It cuts through three counties - and has three House seats, two held by Democrats. Republican candidates for Ohio's U.S. House seats won 58 percent of the votes but 75 percent of the seats. "Their problem is weak candidates who run poor campaigns based on bad ideas, not the districts", said House Speaker William J. Howell spokesman Christopher West.
Still, experts say, Republicans generally benefit far more from gerrymandering than Democrats, since they hold control of the majority of state legislatures and governors' mansions.
Redmon said political "apathy" and eight-year term limits are partly to blame for a lack of candidates, as potential challengers simply wait until incumbents can no longer seek re-election.
Legal efforts by Democrats and others to undo the 2011 boundaries have met with mixed success.
The next round of redistricting will be after the 2020 census, and it could be a very different process.
Former Republican state Rep. Jeff Kottkamp sat on the House committee that redrew House maps. The gap represents the percent of seats won by Republicans beyond what would be expected based on their statewide average share of votes.
The methodology has been cited as "corroborative evidence" in a ruling that Wisconsin Republicans engaged in unconstitutional partisan gerrymandering for state Assembly districts. The U.S. Supreme Court said it will hear that case, potentially affecting voting across the U.S. The formula essentially measures and compares each party's wasted votes those going to the victor in excess of what's needed for victory in an election and shows that Virginia's GOP votes are more efficiently spread out than Democratic votes.