Stephan:   A massive change is underway in American society that is going to fundamentally alter our politics, yet is occurring with almost no notice except to researchers. In as little as two decades 49.5% of the population will live in eight states, as this careful fact-based report lays out. There will also be a very dramatic age differential. It is going to have a huge effect on the congress. The House will be radically restructured, with 42 states having fewer Representatives. But it is in the Senate that I think the greatest effect will be felt and the entire structure established by the Constitution called into question.  Each state regardless of population has two senators, and yet we we are going to have senators representing perhaps 100,000 people while other senators represent tens of millions. This is not what the Founders had in mind. In my view we are headed to a Constitutional crisis, and it will occur just as climate change really begins to bite, a variable this report does not really factor in, and which will create the three big internal migrations that are coming making this story even more complex.