So how did House Republicans manage to hang onto power, despite losing the popular vote for House seats? One answer: through gerrymandering – the calculated redrawing of congressional districts to maximize the impact of their own political constituencies.
As Mother Jones recently explained: "After Republicans swept into power in state legislatures in 2010, the GOP gerrymandered key states, redrawing House district boundaries to favor Republicans. In Pennsylvania, Democratic candidates received half of the votes in House contests, but Republicans will claim about three quarters of the congressional seats. The same is true in North Carolina. More than half the voters in that state voted for Democratic representation, yet Republicans will fill about 70 percent of the seats. Democrats drew more votes in Michigan than Republicans, but they'll take only 5 out of the state's 14 congressional seats."
Others are quibbling with that thesis. Over at The Monkey Cage blog, Eric McGhee argues that redistricting likely accounted for less than half of the gap between the two parties' overall vote share and seat share. The bigger factors, he posits, were incumbency and the fact that much of the Democratic vote tends to be clustered together in urban centers, leading to huge margins of victory in those areas that essentially "wastes" votes.