The initialization "WASP" stands for White Anglo-Saxon Protestant. These are the people who have traditionally run the United States, as the descendants of the original British colonizers. In many cases, it was also easily substituted for "the Establishment," a term often used for the East Coast Ivy League-educated elites who used to run foreign policy and both the State Department and the CIA. In recent years, the hold of the WASPs has diminished, much to the chagrin of some racists.
While the term was originally used to talk about the elite position held by some WASPs, today it is a mildly derogatory one. It has connotations of boring people with no real culture living plastic existences while forever chasing after something "real". A synonym for this derogatory usage is "white bread".