U.S. Naval Academy graduate, Vietnam Veteran, U.S. Senator from Arizona.

He followed Barry Goldwater as Arizona senator in a987, but was more moderate than Goldwater.
McCain at times has had a media reputation as a "maverick" for his willingness to disagree with his party on certain issues.
Campaign finance reform was one of his signature concerns, which eventually resulted in passage of the McCain–Feingold Act in 2002.
He labeled the Supreme Court's 2010 Citizens United v. Federal Election Commission decision as "uninformed, arrogant, naive", and, decrying its effects and the future scandals he thought it would bring, said it would become considered the court's "worst decision ... in the 21st century".

In 2003, McCain and Joe Lieberman co-sponsored the Climate Stewardship Act that would have introduced a cap and trade system aimed at returning greenhouse gas emissions to 2000 levels; the bill was defeated with 55 votes to 43 in the Senate.

He was a candidate for president in 2000 and toured on a campaign bus called the Straight Talk Express. One reporter later recounted that, "McCain talked all day long with reporters on his Straight Talk Express bus; he talked so much that sometimes he said things that he shouldn't have, and that's why the media loved him."

After winning the New Hampshire primary the Republican establishment was worried that a victory in South Carolina would derail George Bush's campaign. A variety of interest groups that McCain had challenged in the past ran negative ads. The New York Times called it "a painful symbol of the brutality of American politics"

In 2008 he was supposedly approached by John Kerry, the democratic candidate running against George Bush, to be Vice President. McCain never confirmed that.

He was the Republican candidate for president in 2008 and was defeated by Barack Obama.

Links:
John McCain - Wikipedia