Election 2008

Sen. John McCain of Arizona, who turns 72 in August, would be the oldest person to take office as a first-term U.S. president.

Sen. Barack Obama of Illinois, who turns 47 in August, would be the first black U.S. president as well as one of the youngest.

Obama, a former Illinois state legislator, was elected to the Senate in 2004. McCain, a former Navy fighter pilot and prisoner of war in Vietnam, was elected to the Senate in 1986, after four years in the House of Representatives.

McCain has accused Obama of being naive in opposing the Iraq war; Obama has charged that McCain was reckless in helping President George W. Bush get the United States into a war now in its sixth year.

McCain opposed tax cuts Bush got through Congress in his first term, saying they favored the rich. But he now backs extending the tax relief, saying to let the cuts expire after 2010 would amount to a tax hike.

Obama backs extending tax cuts for the middle-class but not the wealthy.

McCain has amassed a record of legislative achievement, including a landmark bill to tighten controls on campaign financing, a signature issue. He also helped lead the charge to normalize trade relations with former foe Vietnam.

As a relative newcomer to the Senate, Obama has a shorter record of accomplishments though he has helped lead a charge to tighten ethics rules in the scandal-hit Congress.

McCain and Obama have backed efforts to aggressively address global warming and have criticized the Bush administration's inaction.