MIAMI — In the 2012 election, Democratic candidates for the House of Representatives tallied more votes, nationwide, than Republicans. But Republicans won more seats—33 more, in fact, for a decisive majority. Plenty of observers and analysts attribute the discrepancy to gerrymandering.
New research by Jowei Chen of the University of Michigan and Jonathan Rodden of Stanford University, though, suggests that political geography was more important than partisan redistricting in shaping the national result. At the same time, Chen and Rodden found signs of successful partisan gerrymandering in individual states—a result with important implications for ongoing court battles, as in Florida. Reporters covering redistricting and gerrymandering in any state should take a look at the research and add Chen and Rodden to their source lists.
The academics’ approach was to run thousands of computer simulations of legislative districts drawn without partisan influence, and compare them to the actual districts in 49 of the 50 states. (They did not have access to the precinct-level voting data they needed to analyze Oregon.) Chen and Rodden found that Republicans didn’t need to rely on gerrymandering to win the House, even while attracting fewer votes—current geographic patterns in the United States favor the GOP because Democrats are clustered in urban cores, college towns, and manufacturing centers where unions have historically been strong. As they explained in a recent New York Times op-ed: “In the vast majority of states, our nonpartisan simulations produced Republican seat shares that were not much different from the actual numbers in the last election.”
But they did find districts that appear to be gerrymandered for partisan purposes, with meaningful seat swings in some states—mostly favoring Republicans, but some to the advantage to Democrats.
The Times piece was necessarily short, but in an interview with Chen and Rodden, I found they have a wealth of information that could help local reporters frame their stories, especially in states like Florida, where the redistricting process has landed legislators in court.
Florida is unique in a couple ways. While partisan gerrymandering is legal in some places—Texas is defending itself against a voting-rights lawsuit by arguing its maps were simply designed for partisan advantage—voters in Florida passed a pair of constitutional amendments designed to outlaw the practice. Florida is also where Chen and Rodden concentrated much of their research; when examining the 2012 election in Florida, they ran computer simulation of the maps drawn in 2010 more than 1,000 times. (Their most recent research, which is not yet published in an academic journal, builds on work the pair published last year in the Quarterly Journal of Political Science.)
And it turns out, Chen and Rodden found some Florida results that simply don’t make sense under the state’s mandate for nonpartisan district-drawing.
“Florida is one of the most remarkable states in terms of Republican gerrymandering,” Chen told me. “Even after accounting for natural geographic bias and the Voting Rights Act”—which creates majority-minority districts and can in the process boost Republican seat share by further clustering Democratic voters—“Florida is still a significant outlier.” For example, they found several gerrymandered districts in the Miami and Tampa/St. Petersburg areas that were drawn to favor Republicans.
Chen and Rodden have also found examples of what appears to be successful Republican gerrymandering in other states, including Texas, North Carolina, Pennsylvania and Michigan, as well as examples of apparently successful Democratic gerrymandering in California, Maryland and in districts around Chicago. They can drill down into their data set to look at specific Congressional districts; they’re also able to look at state legislative districts.
And they’re happy to discuss their results with reporters. Chen can be reached at email@example.com; Rodden is at firstname.lastname@example.org. If you’re on this beat, keep on eye on this research, and drop them a note sometime.
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