The Stand is a novel by Stephen King. In it, the population of the United States is decimated by a mysterious plague. Those that are left are called by dreams to either of two cities, Las Vegas (the evil people) or Boulder, Colorado (the good people). The evil people attempt to get a nuclear bomb.
There is a lot more in the novel, and it is very long and frightening, but I have put the pertinent points to my analogy in this synopsis.