Analysis: Did Gerrymandering allowed Republicans to win less votes but still maintain a Majority in the House of Representatives?

by Colonel on November 15, 2012

In a pre-Election prediction by Princeton’s Dr. Sam Wang, he argued that Republicans could lose the popular vote in the House of Representatives and still maintain a majority number of seats:

Copyright 2012 Princeton University

Kevin Drum of Mother Jones summarizes Dr. Sam Wang’s conclusions:

  • Prior to 2010, there was no systematic, nationwide effect from gerrymandering. (See here for more on this.) There was an incumbency effect, in which the majority party has a tendency to keep its majority, but otherwise no net lean in the direction of either Democrats or Republicans when you account for district lines in all 50 states.
  • The 2010 redistricting was more one-sided than in past years.
  • As a result, there’s now a net, systematic, nationwide lean in the direction of the Republican Party. The size of their advantage is calculated as the average vertical distance between the red and black lines in the chart on the right, which turns out to be 6.3 seats.

So the 2010 redistricting really wasunusually partisan. But the size of the Republican advantage turns out to be about six seats, very similar to what Eric McGhee came up with. The incumbency effect is about double that, for a total built-in Republican advantage of roughly 20 seats. Accounting for uncertainty, the Republican advantage is 10-30 seats, which is right in line with how much they outperformed the popular vote this year.

” — Copyright 2012 Mother Jones

Nick Baumann of Mother Jones also explains:

Because the census was taken in 2010, GOP control of state legislatures and governors mansions around the country gave Republicans the power to draw congressional district lines largely as they chose. They seized that chance, aggressively gerrymandering so as to protect Republican incumbents and endanger any remaining Democrats. The Dems would have done the same thing, of course, had they won control of these crucial states in 2010. But they didn’t.

Here are the numbers for states that Obama won or came close and where Republicans drew the congressional map:

  • North Carolina, which Obama lost by around 2 percentage points: 9-4 GOP
  • Florida, which Obama won by around half a percentage point: 17-10 GOP
  • Ohio, which Obama won by nearly 2 percentage points: 12-4 GOP
  • Virginia, which Obama won by around 3 percentage points: 8-3 GOP
  • Pennsylvania, which Obama won by more than 5 percentage points: 13-5 GOP*
  • Wisconsin, which Obama won by 6 percentage points: 5-3 GOP
  • Michigan, which Obama won by 8 percentage points: 9-5 GOP
” — Copyright 2012 Mother Jones

And from “The Votemaster” at

“Although not all House races have been settled yet, it is likely that the number of Republicans in the House will be at least 40 more than the number of Democrats. Yet about as many people voted for a Democrat for Congress as voted for a Republican. How can this be? The answer in a word is “gerrymandering.” The 2010 elections put the Republicans in charge of redistricting in many states and they did an excellent job of drawing the district lines to favor themselves so that even in the event of an evenly split vote they would come out ahead. The only way to make the process fair is to have a nonpartisan commission draw the district lines as happens in California and some other states. But, of course, states where one party has all the power are not likely to do that unless the voters mandate it via a referendum, which is what happened in California.” — Copyright 2012

However, as Frank James of Capital Public Radio reports, Geography, not Gerrymandering, may be at-fault:

Some political experts believe there’s an easier explanation, and perhaps a tougher one for Democrats to overcome: Voters supporting Republican House candidates, they say, are spread over more congressional districts than those who support Democrats. It’s that simple. It’s merely a matter of geography.

Democratic voters tend to be concentrated in fewer areas on the map relative to Republicans, according to these experts.

“What’s so striking to me is that nonwhite voters are sufficient to allow Democrats to win statewide races increasingly. And we elect both the Senate and president on statewide races. But nonwhite voters are so clustered in so few congressional districts around the country that Republicans have a built-in advantage to win the House,” said David Wasserman of the Cook Political Report, in a post-election panel discussion at the Bipartisan Policy Center, a Washington think tank.

“It’s not an accident, it’s not random, that the presidency and the Senate stayed in Democratic control and the House stayed so strongly Republican,” said Wasserman.

While Democrats held a House majority as recently as 2010, the geography-favors-Republicans theory sets up the prospect of divided government for the foreseeable future (assuming Democrats can retain control of the presidency and/or Senate).

Democrats entered Election Day with 193 House seats and needing 25 to reach the 218 to retake control of the chamber. They fell short of that goal, though they fared better than many analysts expected, now holding 195 seats to the Republicans’ 233 with seven races still too close to call more than a week after the election.

One piece of evidence: Democrats aren’t necessarily winning seats even in states that have adopted nonpartisan commissions to redraw congressional lines.

In a post on the political science blog called The Monkey Cage, guest blogger Nicholas Goedert, a postdoctoral fellow at Washington University in St. Louis, writes (emphasis in the original):

States that are heavily urbanized (such as New Jersey and Pennsylvania) are more distorted against Democrats than more rural states (such as Minnesota and Wisconsin). Indeed, urbanization has a negative and significant effect on the difference between seats won by Democrats and expected seats, even after controlling for the party in control of redistricting… Of course, this analysis does not imply that Democrats are doomed to the minority for the foreseeable future, or even the next decade. The Pennsylvania map includes five Republican seats won by Obama in 2008, suggesting that a wave of sufficient strength could reverse the delegation’s majority. But because of unequal concentrations of vote share in most states, not just those with Republican gerrymanders, a Democratic majority will be more difficult than it should be. And this difficulty persists even when both parties agree to the maps… Changing our redistricting institutions alone will not assure national proportionality.”

Actually, it’s difficult to envision how Democrats can tackle the issue of voter geography. The only people who typically relocate for voting reasons are politicians themselves, and even that’s not always true.

There does appear to be a glimmer of hope for Democrats when it comes to the House, and, once again, it has to do with Latino voters.

According to Goedert’s analysis, in states with large Hispanic populations, Democrats did about as well if not better than he calculated they would do based on their share of the popular vote. For some reason, Latinos tilted the balance back toward Democrats.” — Copyright 2012 Capital Public Radio

While the Geography argument is compelling, Gerrymandering at least partially contributed to the Republican advantage in the House of Representatives coming out of this Electoral Cycle.

Previous post:

Next post:

Page 1 of 11