Anyone here ever read "The Ten O'Clock People" -- a short story by Stephen King?

http://en.wikipedia.org/wiki/The_Ten_O'Clock_People

The main character, Pearson, is a smoker trying hard to quit for health reasons. He discovers a horrible aspect of reality that only those attempting to quit like him are capable of seeing—that many of the people living among us in positions of power, including many police officers and political figures and even the Vice President of the United States, are in fact inhuman monsters disguised as people. A unique chemical imbalance, caused by his smoking only on his morning break (thus the reference to Ten O' Clock in the title) makes him able to see the true nature of these creatures through their disguises.

There is a subtle comparison to segregation by race in the 1950s...