Out of the 2,800 graduate and research assistants at Columbia University, approximately 1,700 of those people have signed a petition to unionize. The students began meeting regularly to discuss their wishes to unionize, but this notion is slowly becoming a reality. Recently, more than 100 students engaged in a march to the office of Columbia's president to deliver the signed forms.
See "Columbia Graduate Students Push for a Labor Union", Steven Greenhouse, The New York Times, March 3, 2015