http://www.enotes.com/everyday-law-encyclopedia/sexual-harassment
Unheard of until the 1970s, SEXUAL HARASSMENT has become a dominant concern of employers, schools, and other organizations throughout the country. It is one of the most litigated areas of sexual DISCRIMINATION law, and virtually all major companies, government organizations, colleges and universities and even the military now have sexual harassment policies in place. Even the president of the United States has been subject to a sexual harassment lawsuit.
See: Freedom of Association
http://en.wikipedia.org/wiki/Freedom_of_association#United_States_Constitution