John Sidney McCain III (born August 29, 1936)  is the senior Senator from the state of Arizona, having served 20 years after replacing Barry Goldwater in 1986. He is currently the Ranking Member of the Senate Committee on Armed Services.  McCain has announced his intention to declare his candidacy for the Republican nomination for President of the United States in the 2008 Election.
McCain was born in the Panama Canal Zone. He was educated in Alexandria, VA before receiving his Bachelors of Science from the United States Naval Academy in 1958.
McCain served in the United States Navy from 1958 to 1981. He was shot down over Hanoi in 1967 during the Vietnam Conflict and held as a Prisoner of War for seven years. McCain graduated from the National War College in 1974. Upon his retirement from the Navy in 1981, as a Captain, he had been commended with the Silver Star, Legion of Merit, Purple Heart, and Distinguished Flying Cross.
McCain was elected to the House of Representatives from Arizona's 1st district in 1982 and served two terms before being elected to the Senate in 1986. In 2000, he pursued the presidency but lost his bid for the Republican nomination to George W. Bush. He intends to announce his candidacy for the 2008 election in April. 
1. Immigration. In 2005-2006, McCain joined with liberal Senator Ted Kennedy to support a sweeping bill that reformed immigration law. It has not passed.
2. Same-sex marriage. In 2006, McCain joined Democrats and liberal Republicans in voting against the Federal Marriage Amendment, a proposed constitutional amendment to forbid non-traditional marriage. Later, on Hardball, McCain took a Libertarian position, "On the issue of the gay marriage, I believe that people want to have private ceremonies, that's fine." McCain's home state of Arizona was the only state to defeat a marriage referendum (in 2006), as McCain did nothing to support it.
3. "Gang of 14". On May 23, 2005, McCain was part of a group of 14 Senators who blocked the planned "nuclear option" for confirming blocked Republican nominees for the bench. Under this compromise a few judicial nominees were allowed to be confirmed (Janice Rogers Brown, Priscilla Owen and William Pryor), but others (e.g., Henry Saad) remained blocked and had to withdraw.
4. Campaign finance. McCain advocated campaign finance reform, something opposed by many conservative on Libertarian grounds that it interferes with the right to free speech. In 2002, McCain joined with liberal Democrat Russell Feingold to prohibit independent groups from advertising about a candidate within many weeks of an election. This law prohibits ads that do not even recommend for whom to vote, but merely urge people to contact their representatives concerning a vote that the representatives will make in Congress. A court recently declared this unconstitutional. Further, the McCain-Feingold campaign finance law allows Indian nations (which get nearly all their money from unregulated casinos) to make unlimited political donations, even though political donations by American citizens are strictly limited and political spending by corporations is prohibited.
5. Tax cuts. McCain opposed President George W. Bush's tax cuts, on the argument that cutting taxes without also cutting spending was not actually a tax cut, but was a tax on future generations.
6. Criticism of the religious right. In his unsuccessful campaign in 2000, McCain criticized elements of the religious right in an attempt to attract voters.
7. Embryonic stem cell research. McCain supports embryonic stem cell research as a member of the Republican Main Street Partnership.