He became one of the most vocal critics of the Obama administration's handling of the September 11, 2012, attack on the U.S. diplomatic mission in Benghazi, saying it was a "debacle" that featured either "a massive cover-up or incompetence that is not acceptable" and that it was worse than the Watergate scandal. As an outgrowth of this strong opposition, he and a few other senators were successful in blocking the planned nomination of Ambassador to the UN Susan Rice to succeed Hillary Rodham Clinton as U.S. Secretary of State; McCain's friend and colleague John Kerry was nominated instead.