In the 2012 Presidential Election, Democrat Barack Obama decisively defeated Republican Mitt Romney. Obama won 332 electoral votes and the national Presidential popular vote by nearly 4%. Despite this crushing victory, Obama headed into his second term in office without a majority in the US House. House Republicans lost the popular vote by 1% but still won a 234-201 majority in the chamber. This outcome did not surprise shrewd political observers—Republicans held a considerable structural advantage in the US House throughout the 2010s. In fact, according to FairVote, Republicans would expect to win a 241-194 majority in a tied national House popular vote. This means that by only winning 50% of the vote, Republicans were assured a crushing majority in the US House.
Just ten years later, Republicans are left pondering a narrower-than-expected House majority. Although Republicans won the popular vote by 2%, they appear likely to only win a 222-213 majority in the chamber, even after winning two tight races heading to recounts. In 2022, it was Democrats who held a structural advantage in the house—if Democrats tied Republicans in the national house vote, they would have won a 221-214 majority in the chamber. Even after losing control of the US House, Democrats have won a valuable consolation prize: 222 seats could barely be a working majority for Republicans, who will have to reconcile moderate caucus members like Brian Fitzpatrick and Nancy Mace with farther right figures like Marjorie Taylor Greene and Lauren Boebert. What changed in the past ten years? How did Republicans squander their massive structural advantage in the House, and could it worsen in the coming decade?
2022 US House Districts were Ostensibly Biased Toward Republicans
Even more casual political observers are aware of gerrymandering and generally understand that the US House has been biased against Democrats since the 2010 census redistricting cycle. In the past few weeks since Election Day on November 8th, many people have publicly assumed that (based on the narrow nature of the Republican House majority) gerrymandering cost Democrats the US House. But as highlighted above, this is not the case. The median house seat (IA-03) voted to the nation’s left by about 1.5%.
The 2022 congressional map was supposed to be biased toward Republicans. As highlighted by FiveThirtyEight’s Nathaniel Rakich, effective Republican gerrymanders in Texas, Florida, Ohio, and Georgia fueled this advantage. FiveThirtyEight modeling projected that “if the national House popular vote were perfectly tied, Republicans would theoretically win 225 seats and Democrats would win 210.” This structural advantage is a far cry from 2012 when FairVote expected that Republicans would win 241 seats in a tied national House popular vote), but is still considerable.
The US House structural bias was more favorable to Democrats than expected for three reasons. First, as a byproduct of their previous house majority, Democrats held an incumbency advantage in most competitive districts. Republicans had to bear the burden of flipping Democratic seats to win the chamber. This challenge certainly cost Republicans several seats, where strong Democratic incumbents resisted national trends and held their Trump-won districts even as the nation shifted six points to the right. To compound the issue, Republicans did not even take advantage of the incumbents they could have had. Supported by Donald Trump, loyalist Republicans Joe Kent and John Gibbs led ousters of popular and electorally successful incumbents Jamie Herrera-Beutler and Peter Meijer, handing two districts to Democrats. Second, Democratic gerrymanders were highly effective. While Democrats could only pass optimal partisan gerrymanders in four states (Oregon, Nevada, New Mexico, and Illinois), they took advantage of the opportunity with clinical efficiency. Democrats won 24 of 30 (80%) of seats in these four states, despite only winning 54% of the combined house popular vote (controlling for uncontested districts). The third and final reason is the most worrisome for Republicans: the new Republican coalition—built by Donald Trump—is not remotely designed for success in the US House.
Fast Fact: Although recent political realignment has allowed Republicans to acquire a massive structural advantage in the US Senate, it is helping Democrats counteract gerrymandering and gain a structural advantage in the US House.
Why are Republicans Developing A Geographic Disadvantage in the House?
1. In 2016, Trump Swept Rural America
While Republicans were successful in rural America well before Donald Trump arrived on the political scene, it was not until the 2016 Presidential Election that the party began to dominate the regions. In 2012, Democrats wasted far more votes than Republicans in blowout House races. While 30 Democrats won their race by 60 points or more, only 7 Republicans won by the same wide margin. The 2016 election was an election of regional polarization: very blue areas (generally cities) became bluer, and very red areas (generally more rural areas) become redder. In the 2012 presidential election, only ~33% of Americans lived in a “non-competitive” area, a county where either Democrats or Republicans won >65% of the vote. But in 2016, this number increased to 43%. Democrats did boost their numbers in heavy blue areas, but it was Republican success in rural areas that primarily drove this increase, closing the gap between the two parties in wasted votes.
Ancestral rural Democrats across the country, particularly in the Midwest, left their party in droves for Trump and the GOP. For the most part, Republican House candidates did not need this marked improvement in the reddest areas, these were the districts Republicans were already holding easily. Of course, some of these rural voters were districted with blue areas and did contribute to battleground seats, but most of these rural improvements were turning 50-point wins into 60-point wins for the GOP.
2. In 2020, Republican Gains Were Concentrated in Deep Blue Areas
Although Republicans disproportionately improved in very red areas in 2016, serious problems did not start to develop until 2020. Partisan realignment since 2016 (educational polarization and racial depolarization) has proven to be disastrous for the GOP in the House. To oversimplify American politics, the safest blue districts tend to be in cities, and the safest red districts tend to encompass rural areas and small towns. The battleground districts are disproportionately located in high-education suburban areas, where Republicans are slipping. Conversely, Republicans enjoy higher and higher levels of minority support as Black and Hispanic voters trend toward the party. Dividing all counties into five categories, ordered by the highest to the lowest proportion of the vote won by Biden, Trump only gained between 2016 and 2020 in the bluest counties. To make matters worse, Democrats gained the most in the most competitive counties.
Republicans will have to grapple with the uncomfortable reality that trading a suburban vote (in a competitive House district) for an urban vote (in a deep blue House district) deeply harms their ability to hold a geographic advantage. If educational polarization continues at this rate, it could be Democrats that hold a significant advantage in the US House by the end of the decade—but not because of gerrymandering.
Author’s Note: As is the norm in this type of analysis, all statistics regarding the “US House National Popular Vote” have been adjusted for uncontested seats. For example, the article notes that “Republicans won the  popular vote by 2%,” despite the raw number being closer to 3%. This is because Republicans only left 3 seats uncontested, while Democrats left 13 seats uncontested.