The 2012 national election continues to be a puzzle. Barack Obama won reelection with a solid 51 percent of the vote, and Democrats picked up 2 Senate seats, expanding their majority to 55-45. Yet the House of Representatives remained in Republican control, 234-201, yielding the divided government we have today. …
The GOP advantage in 2012 was noteworthy because the party lost the popular vote while retaining a majority of seats, but its advantage was no larger than previous majority parties have enjoyed. …
A more salient point is that the House seems to have developed a structural Republican tilt that has grown in recent cycles. It springs from the way the lower chamber is elected: in geographically based, single-member, winner-take-all districts, favoring coalitions whose votes are broadly distributed and disfavoring constituencies that are concentrated. [cont.]
Jay Cost, The Weekly Standard