Last week, Republican presidential candidate Donald Trump warned Fox News’ Sean Hannity that the “election is going to be rigged.” He may be more right than he thinks.
After a well-received convention and a week where her Republican rival vacillated between attacking a gold star family and antagonizing his own party’s leaders, former Secretary of State Hillary Clinton leads Trump by 7 points, according to Real Clear Politics’ polling average.
That’s the good news for Democrats.
The bad news is that, even if Democratic House candidates were to match this performance this November, outperforming their Republican candidates by an average of 7 points nationwide, it is likely that Republican Speaker Paul Ryan will retain control of the U.S. House of Representatives next year. Voters could hand a substantial electoral victory to Democrats this fall, but the Party of Trump would still be favored to retain the House.
Indeed, Republicans captured the House quite recently, despite the fact that their House candidates lost the national popular vote. In 2012, Democratic candidates outperformed Republican candidates nationwide by more than a full percentage point. Nevertheless, Republicans entered the 113th Congress with a 33 seat advantage in the House.
A party needs to control 218 seats in the House to command a majority. The median member of the House in 2012— that is, if you listed all House races in order from biggest Republican landslides to the biggest Democratic landslides the 218th member of this list— was Rep. Robert Pittenger (R-NC). Pittenger won his race by more than six percentage points, 51.78 percent to 45.65 percent. Based on this datapoint, as well as the fact that Democrats outperformed Republicans by over a percentage point, ThinkProgress estimated that “in order to take control of the House, Democrats would have needed to win the 2012 election by 7.25 percentage points.”
The reason for this is twofold. First, after the GOP’s strong performance in 2010, Republicans used their control of state legislatures and governor’s mansions to draw congressional maps that entrenched Republican power and minimized Democratic representation in Congress. In 2012, the first election run after this redistricting, these maps enabled Republicans to hold commanding majorities in many swing-state congressional delegations, even though Democratic President Barack Obama received a majority of each state’s presidential votes:
The second reason why House elections favor the GOP is more subtle but at least as significant: geography. Democrats tend to cluster in geographically compact cities, while Republicans tend to be spread out more in rural and suburban congressional districts. As Ruy Teixeira explains, after the 2012 elections, Democrats controlled “87 of the 100 smallest Congressional districts, while the GOP [held] 73 of the 100 largest districts.” This produced a national map where Republicans held “districts covering 80 percent of the US land mass (!), compared to the Democrats’ measly 20 percent.”
This matters because legislative mapmakers have traditionally favored districts that are compact and that group historic neighborhoods together. And congressional maps that comply with these traditional criteria are more likely to survive a court challenge than maps which depart from them. Thus, even honest mapmakers who are not seeking to give one party and advantage over another will tend to draw maps that favor Republicans. Geography gives the GOP a built-in advantage, at least under the traditional criteria.
If Secretary Clinton does defeat Trump, one of her first tasks as president is likely to be choosing a new Supreme Court justice to replace the late Justice Antonin Scalia. Whoever Clinton appoints could be the fifth vote to strike down partisan gerrymanders.
Should this happen, however, it will matter a great deal whether a future Court decision outlawing partisan congressional maps adheres to traditional criteria such as compactness, or whether it favors maps which genuinely give no unfair advantage to either party. If the Supreme Court emphasizes the traditional criteria, then their effort to end gerrymandering could have the ironic effect of entrenching a build-in advantage for Republicans.