Ballotpedia releases margin of victory analysis for 2012 congressional elections

From Ballotpedia
Revision as of 17:03, 13 July 2013 by Leslie Graves (Talk | contribs)

Jump to: navigation, search

January 29, 2013


By Ballotpedia's Congressional team

MADISON, Wisconsin: After the 2012 elections, groups across the country placed strong correlation between the Republicans maintaining control of the U.S. House and the gerrymandering of districts following the 2010 Census. A memo from GOP leadership as well as news stories and blogs attributed the Republican majority in the House to a choreographed effort to rig districts in their favor.[1][2][3][4]

Examples like Pennsylvania and Virginia -- where President Obama won the state but the GOP holds more congressional districts -- have been used to point to the impact of redistricting. In Pennsylvania, Republicans hold 13 of 18 congressional seats. But President Obama won the state overall by five percentage points. In Virginia, Republicans represent eight of 11 congressional seats, despite President Obama winning the state by four points. Redistricting played a part in this breakdown, as does the general population breakdown in each state, with Democratic-leaning voters tending to live in densely-populated cities.

Whether it is redistricting, population migration, or a combination of both, the results of the past election paint a picture of how difficult the road will be for Democrats to re-take the US House. Based on Ballotpedia's margin of victory analysis, Democrats would have needed to win all 30 races decided by fewer than five percentage points -- as well as an additional five races decided between 5 and 10 percentage points -- in order to win control of the U.S. House.

Seats won by each party based on margin of victory in 2012 United States House of Representatives Elections
Party 0-5% points 5-10% points 10-20% points 20% points or more
Electiondot.png Democratic 18 15 23 145
Ends.png Republican 12 18 64 140
Totals 30 33 87 285

Ballotpedia staff analyzed the margin of victory in the 435 US House races. The methodology was as follows -- certified election results were used to obtain the difference in votes between the winner and the second-place finisher. For example, in the closest race, North Carolina's 7th District, incumbent Democrat Mike McIntyre defeated David Rouzer (R) by 654 votes in a district where 336,736 total votes were cast, yielding a margin of victory of 0.2 percent. The U.S. Senate was also analyzed, and that analysis can be found here.

According to our analysis, Democrats actually won more of the closest races, taking just over half of races which had a margin of victory of 10 percent or less (33 of 63). For example, incumbent Democratic representative John Barrow won re-election by seven percentage points, 53.7 percent-46.3 percent over the second-place finisher, Lee Anderson (R). This race is considered competitive because the margin of victory for Barrow was less than 10 percentage points.

However, Republicans did overwhelmingly dominate the 87 races with a margin of victory between 10 and 20 percent. Of those 87 seats, 23 were won by Democrats, while the remaining 64 were claimed by Republicans. The remaining 285 races are considered extremely uncompetitive because the margin of victory was greater than 20 percent. In these 285 seats, the results were once again nearly-evenly distributed between Republicans and Democrats. Democrats took 145 of the seats, while Republicans won 140.

The average margin of victory across all congressional districts was 31.85 percent, meaning that on average the winner of each race received nearly twice as many votes as the top opponent. The average margin for Democratic victors was 35.7 percent, which is significantly higher than the Republican figure of 28.6 percent.

Earlier in the campaign season, Ballotpedia analyzed the contested nature of congressional primaries, finding that only 51.81 percent of congressional incumbents faced a primary opponent.

For the full margin of victory analysis of each congressional race, click [show] on the table below.

See also