Anyone interested in truly understanding why Democrats won a majority of the national popular vote for the U.S. House but made only small gains against the GOP majority won in 2010 should read a guest post by Washington University’s Nicholas Goedert at that fine political science site The Monkey Cage. The bottom line is that it appears gerrymandering was responsible for a lot, but by no means all, of the disproportionate haul of House seats by the GOP. That old devil, “relatively inefficient vote distribution,” had an impact as well.

In a careful analysis of House results in states where Republicans did and did not control redistricting, Goedert made these findings:

In every state districted by Republicans, Democrats won fewer seats than their historical expectation, and in six cases they underperformed by 20% or more (as a percentage of total seats up for election). So it appears that Republicans gained benefits across the board from controlling the redistricting process.

By contrast, Democrats exceeded their expected seat share only slightly in the three states where they controlled the process….

But partisan control of redistricting cannot completely explain each party’s performance relative to the hypothetical unbiased map. Instead, we still observe bias even where we should expect none in the redistricting process….Democrats also fell short in several states with bipartisan or court-drawn maps, winning on average 7% fewer seats than expected.

In another indication that Democratic voters are simply concentrated too much geographically to produce representative results, Goedert found that Democrats fell short more in urban than in rural states. And in an especially intriguing data point in terms of future voting trends, he noted that Democrats did better as compared to the popular vote distribution in states with large areas dominated by Latino voters:

It is possible that nonpartisan commissions may have contributed to greater fairness, but the ease of drawing geographically large, majority Hispanic districts in these states, (e.g. AZ-2, CA-16, CA-51, and TX-23) might have also mitigated the natural advantage Republicans have in other regions in the distribution of the their vote.

This isn’t grounds for any sort of Democratic despair: the “inefficient vote distribution” problem is not new, and during the last decade, despite another GOP-dominated redistricting cycle, Democrats managed to unravel an “unassailable” GOP advantage in the House by 2006 (though there is some evidence Republicans in that redistricting cycle overreached instead of defending vulnerable incumbents, which made them especially susceptible to a big Democratic “wave”). A bigger question for 2014 is probably whether the ever-closer alignment of the two parties with elements of the electorate that are significantly more (older white voters) and less (young and minority voters) to vote in midterm elections. But add together that problem for Democrats with the redistricting and vote-distribution problems and you can see why a Democratic House in 2014 might be a real reach, even as long-term trends continue to benefit the Donkey Party.

Our ideas can save democracy... But we need your help! Donate Now!

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.