Neal Kumar Katyal is an American lawyer and chaired professor of law. He served as Acting Solicitor General of the United States from May 2010 until June 2011. As Acting Solicitor General, Katyal succeeded Elena Kagan, who was President Barack Obama's choice to replace the retiring Associate U.S. Supreme Court Justice John Paul Stevens. Katyal was the Paul and Patricia Saunders Professor of National Security Law at Georgetown University Law Center and the lead counsel for the Guantanamo Bay detainees in the Supreme Court case Hamdan v. Rumsfeld, which held that military commissions set up by the Bush administration to try detainees at Guantanamo Bay "violate both the UCMJ and the four Geneva Conventions." While serving at the Justice Department, he argued numerous cases before the Supreme Court, including his successful defense of the constitutionality of the Voting Rights Act of 1965 in the landmark case, Northwest Austin v. Holder.