American culture has always had an anti-intellectual component. The country was initially settled by merchants and religious fanatics, two groups not exactly known for intellectual curiosity. What's more interesting is how successful intellectuals have been in this country, considering half the population has generally held them in contempt.

This book is a bit dated but is a pretty good history of American anti-intellectualism:

http://www.amazon.com/Anti-Intellectualism-American-Life-Ric...

Anti Intellectualism has never been "relegated to a small percentage of trouble makers." It's always been a popular ideology in American culture.

http://www.amazon.com/Anti-Intellectualism-American-Life-Ric...

If you went to a public school in the USA where anti-intellectualism was NOT the dominant meme, consider yourself lucky...