John McCain is a politician.
John Sidney McCain III ( born August 29 , 1936 ) is an American politician who currently serves as the senior United States Senator from Arizona . He retired from the Navy as a captain in 1981 and moved to Arizona , where he entered politics . Elected to the U.S. House of Representatives in 1982 , McCain served two terms . He secured the nomination in 2008 after coming back from early reversals , but was defeated by Democratic candidate Barack Obama in the general election , losing by a 365 -- 173 electoral college margin and by 53 -- 46 % in the popular vote .