"We face formidable challenges, but I'm not afraid of them. I'm prepared for them," said the four-term Arizona senator, ex-Navy pilot and former Vietnam captive.
In a speech in the first-in-the-nation primary state, McCain stressed the wisdom he's acquired over time rather than the decades themselves as he sought to make the case that he's the most qualified to succeed President Bush amid challenges at home and abroad.
"I'm not the youngest candidate. But I am the most experienced," said the 70-year-old who could be the oldest first-term president, drawing cheers. "I know how to fight and how to make peace. I know who I am and what I want to do."