President Obama got 51.4% of the popular vote and won essentially every swing state. Democrats probably picked up two votes in the Senate, even though more Democrats had to defend their seats. Yet Republicans will likely end up with a 35-vote majority in the House, in spite of the fact they got less than 50% of the votes that were cast for major party candidates.
Nationally, Republican candidates for the House probably got 500,000 fewer votes than Democrats. That’s just 49.7% of the major party vote. Republicans still managed to win a majority in the House in part because that vote total doesn’t really account for all the races. More Republicans ran unopposed, presumably because Democrats didn’t think they could win in those districts. If those uncontested seats had been real races that people voted on, Republican candidates for the House probably would have won the national popular vote.
In other words, by not contesting as many races, Democrats essentially started Election Day five seats down. If Republicans had just won 49.7% of the contested races, they would have picked up enough seats for a two- to three-seat majority in the House. In that sense, Republicans probably deserved to win the House, even though Democrats won a majority of the votes that were cast in the competitive races.
But Republicans also benefitted from the way the districts were drawn in large swing states. There were four states without any uncontested races—Michigan, North Carolina, Pennsylvania, and Wisconsin—where the Democratic candidates received a majority of the votes but Republican candidates won a majority of the seats. Republicans got just 49% of the vote in those four states, but won 36 seats while Democrats won just 17. That's about 10 more seats than Republicans would have been expected to win on the basis of the vote totals alone. There were no states where Republicans received a majority of the votes but Democrats won a majority of the seats. In Ohio and Virginia—states that went for Obama—Republicans did manage to win a slight majority of the votes cast in House races. But they also managed to win around 6 more seats than would have been expected to on the basis of the state vote totals alone.
In each of those six states, the districts were effectively gerrymandered—drawn so that Democrats were concentrated into just a few districts, while Republicans were spread in a thin majority through the rest of the state. Taken together, those six states account for the entire difference between the number of seats Republicans actually won and the number of seats they should have won on the basis of the popular vote.
The bottom line is that, as a group, Republican candidates for the House outperformed Democrats by enough to earn them a very small majority in the House. The enormous amount of Super PAC money that was spent this year may have had diminishing returns in the presidential race, but it likely made a real difference in the House races. But Republicans probably still wouldn't have had more than a few seat majority in the House, if congressional districts weren't rigged in their favor in key states.
Folllow me on Twitter: @rdeneufville
John Boehner image from Gage Skidmore