McCain first said that the "final decision" on ending a pregnancy would be made by his daughter, 15. An hour later, he contacted reporters with a clarification: "I misspoke," he said. "The family decision will be made by the family, not by" his daughter alone, he added.

Later yet, he said, "It's a family decision, not her decision and that's pro-life," he said. "Cindy (his wife) and I will make that decision."

McCain grew testy when reporters continued to press him during the day. "What's the matter with you, sir," he said at one point. "I've answered your question, sir."

He declined to answer when asked what would happen if his daughter became pregnant as the result of rape or incest.

"We have a 15-year-old daughter," Cindy McCain said when the question was asked, before abruptly moving away from reporters.

McCain said his wife, who was traveling on his campaign bus at the time, would call their daughter at school in Arizona to talk to her about why her name might be in the news. "I do worry, understandably, about my 15-year-old daughter. I hope this won't have an impact on her," he said.

The abortion issue has flared in recent days, as the GOP presidential field moves through the opening round of primaries and caucuses. Front-runner George W. Bush, pressed repeatedly last week, said the Supreme Court's 1973 ruling legalizing abortion usurped rights properly belonging to the states, and the individual legislatures should be able to decide what restrictions, if any, to place on abortion.

Conservatives Steve Forbes, Gary Bauer and Alan Keyes are firmly opposed to abortion, and favor overturning the court's decision.

"My daughter has been raised to believe that that's God's decision, and that it's already been made," Keyes said Wednesday. "And, therefore, I have no fear of what she would do."

Bush and McCain, while both expressing opposition to abortion, have adopted more nuanced positions, apparently in hopes of broadening their political appeal.

McCain has adopted a highly unusual campaign style, spending long hours on a chartered bus in New Hampshire in close proximity to reporters, often bantering good-naturedly and rarely refusing to answer questions.

A reporter aboard his "Straight Talk Express" campaign bus first posed the question: If his 15-year-old daughter became pregnant and believed that she wasn't ready to bear a child, would McCain block her from getting an abortion?

"No," the Arizona senator.

The issue dogged McCain throughout the day and followed him to the Republican candidates' final debate before the Feb. 1 primary.

"How can you take the position that you would subject such a choice to a family conference or any other human choice?" Keyes asked McCain during the broadcast. "Isn't it God's choice that protects the life of that child in the womb?"

McCain stood his ground. "I will not draw my children into this discussion," he replied. Later, he fired back at Keyes.

"I've seen enough killing in my life," said McCain, a decorated Vietnam War veteran and former prisoner of war. "I know how precious human life is, and I don't need a lecture from you."

Asked back on the bus whether his comments amounted to an abortion rights viewpoint, McCain said: "I don't think it's the choice position to say that my daughter and my wife and I will discuss something that is a family matter and that we have to decide."

Pressed on the matter, McCain, clearly irritated, shot back: "I'm not gonna talk about what I'm gonna do with my daughter in the most personal and painful kind of situation that I can imagine outside of a terminal illness."

The Arizona senator has said he believes life begins at conception and that he opposes abortion except in cases of rape, incest and when the mother's life is in danger. He pointed out that he has consistently voted against abortion during his 17-year congressional career. McCain also supports parental notification, a law on the books in Arizona where his family lives.

McCain has stumbled over the abortion issue before.

In August, he surprised his staff and angered anti-abortion allies by appearing to suggest that he would oppose repealing Roe vs. Wade, the 1973 Supreme Court decision legalizing abortion.

Under pressure, McCain tried to clarify his views with written statements saying he favors working to overturn the ruling while trying to reduce abortions through adoptions, counseling and other efforts. Whenever McCain is asked about the issue at town hall meetings, he says he wants to reduce the polarizing nature of the debate by encouraging both sides to work together on issues to which they agree, such as improving adoption and foster care systems.