The Big Sort is a book that discusses the segregation / segmentation of American Society. The theory is that since 1965 there has been a significant pattern of internal migration so that people with like values have tended to move to communities with other people of similar values to them. The authors then argue that the political divide has developed as a consequence of this.
Although I think that they argue their case well in terms of establishing that this has occurred - the authors do not make arguments as to how we will bridge the divide and deal with the fact that (as they note) when like thinkers gather together they tend to move to the extreme of their values because of the comfort provided by near unanimity.
