George Bush, June 2002, but the plan or suggestion was in place before 9/11/2001.
See The U.S. Commission on National Security/21st Century (USCNS/21), also known as the Hart-Rudman Task Force on Homeland Security, chartered by Secretary of Defense William Cohen in 1998, for more.
Bush could have stopped it. But hey why waste an opportunity to appoint a political crony to a position. Bush will eventually go down in history as Bill Clinton term three and four minus the Clinton scandals.