The Rice University Neologisms Database

Satirical reference to the western coast of the United States, especially California; so called because of the prevailing liberal attitudes there. Left Coast is frequently used in connection with Hollywood and movie stars, whose political views are usually left of center. Left takes on a multi-dimensional role here, meaning both left, as in left hand, as well as left-wing or liberal. The author of this word wanted to make a humorous reference to the liberals living on the West Coast and their policies, so he coined this phrase from the dual meaning of left. Since the Pacific Coast is the "left" coast of the continental United States, and is known as a center for liberal thought, calling it the LEFT COAST was a quick way to sum up both the location and its social values.