Richard Nixon once warned of an America cut in two, a colony of poor, disenfranchised people within a nation of wealth. His law-and-order policies went a long way to making that a reality. In his new book, A Colony in a Nation, Chris Hayes looks at how fear has led to some destructive policies in America’s cities.    Join Slate Plus! Members get bonus segments, exclusive member-only podcasts, and more. Sign up for a free trial today at Slate.com/gistplus.