If you think America's political warfare has sunk to an all-time low, fast forward with novelist Bert Black and see what happens when fed-up voters choose a third party New American Progressive as President. Sally Macalester wins the popular vote, but not a majority in the Electoral College. So under the Twelfth Amendment the House of Representatives gets to choose, and that's when things get really strange. A clear majority of House members are Republican, but each state gets only one vote for President, and that forces a compromise on Macalester. The Senate, also controlled by Republicans,...