Catholic University Politics Professor Matt Green has two interesting posts [1]up (the one is linked within the other) about the possibility that the Democrats may have won a majority of the votes for Congress this year, but nonetheless were unable to secure a majority of seats. This has only happened once in recent times, in 1996. As Green notes, it is not clear that re-districting is the only or even principal culprit here, but it is the most likely suspect.