Predicting House races is usually the most difficult part of any election. All 435 seats in the House of Representatives are up every two years.
All of these races contain many factors, most that are hard to statistically quantify. The location of the district, the money garnered by both candidates, the composition of the electorate in any given race and the national political climate are just a few of the factors that determine which candidate wins any of the 435 races.
Representatives are derived from the population density of their district, but the districts first must be mapped (or “drawn”). Every ten years, House districts are redrawn after the Census is conducted. Redrawing congressional districts shakes up the House in a big way. In 2010, Republicans gained power in a record number of state houses and won the vast majority of governorships. In seven states, an independent nonpartisan commission redraws the lines in order to limit political bias toward one party or the other. In the remaining 43 states, the new congressional districts are drawn by state legislatures or politically appointed advisory committees. In these states, the governor has the power to veto any possible plan-making.
Governors are the most powerful players in the redistricting process. For decades, if not centuries, the parties in power of the governorships have approved plans to draw districts more favorable to the interests of their political party. The process is known as gerrymandering. Since 2010, these redrawn districts have heavily favored Republican candidates. Given the contours of the current congressional districts, Republicans are likely to retain their House majority until at least 2020 when a new census will be taken.
The redrawing of these districts has led to an outcome where the party that gets the most votes may fail to gain a majority in the House. In 2012, Democratic candidates actually received more votes than Republicans overall, defeating Republicans by a margin of one percent. Despite their victory in the popular vote, Republicans held 33 more seats than the Democrats.
The Republicans are poised to expand their majority by a few seats. In order to simply maintain their current seats, Democrats would have to defeat Republicans in the national popular vote by one percent again. This is almost certain not to happen. In 2012, Democrats benefited from a larger voter turnout due to the Presidential election. Historically, Democrats see a drop off of at least two percent from presidential elections to midterm elections.
Knowing the political contours of the country is also important when predicting the outcome of elections. Rural areas overwhelmingly elect Republican representatives while urban areas overwhelmingly elect Democrats. The fight that decides which party controls the House is fought in suburban districts.
Among these suburban districts, the two parties have clear regional strengths. The South and East Coast often opt for Republican candidates while New England and the West Coast typically votes Democratic. Most of these suburban swing districts are from Midwestern states like Iowa and Minnesota, as well as rust belt states like Pennsylvania and Ohio.
Current polling shows Democrats are slightly favored in congressional elections nationally. An aggregate of all nationally commissioned polls shows Democrats with a narrow lead of less than one percent. But several other factors also need to be considered. Polls that ask what party a voter will choose for their representative fail to take into account the unique circumstances of individual districts. Secondly, President Obama’s approval rating remains low and Republican turnout in midterm elections is usually higher than Democrats.
To put it simply, Republicans are likely to retain control of the House. The question, however, is by what margin. Ultimately, that may come down to a number of high profile retirements in districts that are evenly divided between Democrats and Republicans. 55 members of the House are retiring, 22 Republicans and 33 Democrats. Democrats are likely to gain two seats in California’s 31st district and New York’s 11th district. Likewise, Republicans are likely to gain seats in North Carolina’s 7th district and Utah’s 4th district. 15 toss up seats will determine which party, if any, adds to their congressional caucus. 11 of the vulnerable seats belong to Democrats, two belong to Republicans and two are open seats. Six additional members appear poised to lose their seats, bringing the number of incoming freshman to Congress to over 62.
If Republicans were to run the table and pick up seats of all 11 vulnerable Democrats, they would achieve a majority of 245-190, numbers similar to the composition of Congress after the 2010 elections. If Democrats were to sweep the congressional elections, Republicans would still retain a 231-204 majority. As of now, Republicans appear most likely to gain four seats, creating a 238-197 Republican majority.
This majority has profound political implications. 218 votes are needed to pass a bill. If Democrats want to pass any legislation, they would need the support of 23 Republicans. If Republicans want to pass legislation, they could afford no more than 20 defections from within their own party.
In Congress, Republicans abide by a political tactic known as the “Hastert Rule.” The Hastert rule dictates a bill must only be brought to the floor if it has the support of a majority of the Republican caucus. Since taking the speaker’s gavel, John Boehner has had to violate the Hastert rule six times. 60-70 members of his party vote no on practically all legislation, regardless of pressure from House leadership. Around 150-160 have voted against their congressional leadership on various issues. Boehner’s caucus’ failure to unify has led the speaker to pull a total of six bills from the House floor at the last minute, out of fear the votes weren’t there.
Democrats also have reason to worry. Only about 15 members of the Republican House Caucus have expressed support for part of Obama’s second term domestic agenda. Without congressional votes to form a majority, the rest of Obama’s legislative agenda is essentially dead.
In summary, Republicans will gain four additional seats and likely retain control of the House until at least 2022 when congressional districts are once again redrawn.