John McCain campaigned in the 56th quadrennial presidential election.
John McCain . He was the Republican nominee for the 2008 U.S. presidential election . The United States presidential election of 2008 was the 56th quadrennial presidential election . Democratic Party nominees Barack Obama , a U.S. Senator from Illinois , and his running mate Joe Biden , a long-time U.S. Senator from Delaware , defeated Republican Party nominees John McCain , a long-time and current U.S. Senator from Arizona , and his running mate Sarah Palin , a Governor of Alaska . This election also made McCain currently the only Senator who previously served as a presidential nominee and still remains incumbent , after John Kerry 's resignation from the U.S. Senate in 2013 .