More on Obama's InaugurationIf the unthinkable happens on Inauguration Day, Robert Gates, the defense secretary, will be available to assume the reigns of government. "In order to ensure continuity of government, Defense Secretary Robert Gates has been designated by the outgoing Administration, with the concurrence of the incoming Administration, to serve as the designated successor during Inauguration Day, Tuesday, January 20th," White House press Secretary Dana Perino said.