Pennylvania’s awful gerrymandering of congressional districts (since the post 2010 census redistricting) has ensured that it grossly over-represents Republicans and under-represents Democrats at the Federal level. So this year (2012) Repubs won 13/18 PA congressional districts = 72% of the available representation despite winning only 49% of the vote! (See all data here - you have to add things up yourself at this point):
Total/popular votes for Dem House candidates in PA = 2,702,901
Total/popular votes for Rep House candidates in PA = 2,627,031
PA is truly a travesty of democracy with a downright evil Republican establishment (much anti-Clinton nonsense during the '90s sprang from Western PA) that should shame any principled conservative.
Sadly it’s the same story nationally (modulo recounts and provisionals still to be counted), although corresponding Democratic hackery elsewhere evens things up considerably:
total/popular votes for Democrat House candidates ~ 54 million
total/popular votes for Republicans House candidates ~ 53.5 million
Less than 50% vote share gets the Repubs at least 233 reps, i.e., at least 53% of the House.
The US has much to be proud of politically speaking, but also much that's patently disastrous, completely avoidable, and finally just shameful.