Midterm elections reveal effects of gerrymandering
With an election looming, courts earlier this year declared congressional districts in two states to be unconstitutional partisan gerrymanders. One map was redrawn. The other was not.
The sharply contrasting outcomes that resulted on Election Day in Pennsylvania and North Carolina illustrate the importance of how political lines are drawn – and the stakes for the nation because that process helps determine which party controls Congress.
Pennsylvania flipped from a solid Republican congressional delegation to one evenly split under a map redrawn by court order, contributing to the Democratic takeover of the U.S. House. Despite an almost even split in the popular vote, North Carolina’s congressional dele- gation remained overwhelmingly Republican under a map drawn by the GOP.
“We did everything we could,” Democrat Kathy Manning said. “But we just could not overcome the gerrymandering, and that’s the way the district was designed to run.”
Manning held more than 400 campaign events, contacted tens of thousands of voters and had outspent the Republican incumbent in North Carolina’s 13th District – but still lost by 6 percentage points in a district Republicans drew to favor their candidates.
Partisan gerrymandering has been carried out by both Democrats and Republicans throughout U.S. history. But an Associated Press statistical analysis based on 2016 election data found that more states had Republican-tilted districts than Democratic ones. Some of the largest GOP congres- sional advantages were in North Carolina and Pennsylvania, where Republicans fully controlled redistricting after the
A follow-up AP analysis using preliminary 2018 election data shows the Republican statistical edge was cut in half under Pennsylvania’s new courtordered congressional map but grew even larger in North Carolina.
Republicans and Democrats in this month’s elections split the total votes cast for major party candidates in North Carolina’s 13 congressional districts about evenly, with Republicans getting 51 percent (a figure that is slightly inflated because one GOP incumbent ran unopposed). Yet Republicans won 10 of those races, about three-quarters of the total seats.
That equates to a proRepublican tilt of nearly 26 percent under an “efficiency gap” analysis that provides a statistical way of measuring the partisan advantages that can stem from gerrymandering. That figure was up from about 20 percent in 2016.
By comparison, Democrats in Pennsylvania received 54 percent of this year’s total two-party vote for congressional candidates, including one race where a Democratic incumbent ran unopposed. Democrats and Republicans each won nine seats under a map drawn by the Democratic-controlled state Supreme Court with the assistance of an outside expert.
That marked a significant shift from the 13-5 Republican majority in the state’s congressional delegation during the three previous general elections under a map enacted in 2011 by the Republican-led Legislature and governor.
William Marx, who teaches civics in Pittsburgh, was a plaintiff in the Pennsylvania lawsuit that successfully challenged the Republican-drawn congressional maps.