Sandy Levinson has this provocative post on Balkanization. It begins:

Already articles are appearing suggesting that widely predicted Democratic gains in the forthcoming elections may be vanishing, not least because of the success of the Bush Administration in terrifying the public about the ever-present “global war on terror” and demonizing the Democratic opposition only slightly less, if at all, than “Islamofascists” who are said to be the equal in evil to Hitler and Stalin. So imagine the following possibility: The Republicans retain control of the House by, say, 3-5 seats, all the results of egregiously partisan gerrymanders in Texas and Pennsylvania. And the Senate remains Republican by, say, a single vote, even though Santorum loses in Pennsylvania and Dewine loses in Ohio.