Arizona Sen. and former presidential nominee John McCain has died. He was a Navy pilot in 1967 when his plane was shot down in Vietnam. He spent five years as a prisoner of war. McCain was elected to the Senate in 1986. In 2000, he entered the Republican race for president but lost in the primaries to George W. Bush. In 2008, he became the Republican nominee for president, but lost the general election to Barack Obama. In 2017, he was diagnosed with brain cancer. McCain was 81.