Sen. Elizabeth Warren (D., Mass.) was invited at least three times to speak with Native American students at Harvard Law School while she was a faculty member, but she never accepted, according to a former president of a Native American student group. Dr. Gavin Clarkson, a citizen of the Choctaw Nation who received both a doctorate and a law degree from Harvard while Warren was a professor, says he "personally invited" her three times to visit with Harvard's Native American Law Student Association (NALSA), which he headed while attaining his dual degree.