Laura Bush (search) says gay marriages (search) are "a very, very shocking issue" for some people, a subject that should be debated by Americans rather than settled by a Massachusetts court or the mayor of San Francisco.

Asked how she feels about the issue personally, Mrs. Bush replies: "Let's just leave it at that."

In an Associated Press interview, Mrs. Bush also endorsed sexual abstinence programs (search) for teens, which are slated to get double their current funding under the president's latest budget proposal.

Abstinence should be extensively discussed alongside contraception, she said. "We know it works. It's 100 percent fail-safe."

Mrs. Bush discussed her views as she flew across the country at the start of a three-day trip to raise re-election cash for her husband's campaign and to talk about education. 
 
The trip took her to California where gay couples have been lining up to get marriage licenses in San Francisco. On the East Coast, Massachusetts' highest court recently ruled that the state constitution permits gay marriages.

At the White House on Wednesday, President Bush said, "I'm troubled by what I've seen" in Boston and San Francisco. But he declined to say if he would support a constitutional amendment (search) to ban gay marriages, as conservative supporters expect him to do.

While declining to express her own opinions about gay marriages, Mrs. Bush said, "It's an issue that people want to talk about and not want the Massachusetts Supreme Court, or the mayor of San Francisco to make their choice for them. I know that's what the president thinks.

"I think people ought to have that opportunity to debate it, to think about it, to see what the American people really want to do about the issue."

Mrs. Bush's demeanor is quiet and matter-off-fact, yet she sometimes serves as the president's flak jacket when she's on the road, especially now as his approval ratings are drooping amid Democratic attacks during the primaries.

She defended her husband's credibility and took a shot at Democrats who allege he skipped out on his National Guard (search) duty. "I think it's a political, you know, witch hunt, actually, on the part of Democrats," she said.

The president served honorably in the Texas Air National Guard during the Vietnam War (search) and did report for duty in Alabama where he was briefly assigned, she said.

"He knows that he served honorably," she said. "He knows that he showed up the whole time."

She says she has been hurt by allegations that he lied to the American people about his Guard duty, and by contentions that he misled the public about the extent of Saddam Hussein's weapons when U.S.-led troops went to war in Iraq.

"Nobody likes that part of campaigning - the personal attacks," Mrs. Bush said, sitting on a couch in the private section of her plane. "I certainly don't like it."

On another political subject, asked whether the president's brother, Florida Gov. Jeb Bush, will ever run for president, she replied, "I doubt it, but I have no idea."

Mrs. Bush said she and the president have been feeling a bit "nostalgic" as they watch the Democratic candidates campaigning in the snows of New Hampshire and Iowa.

"That's a much more upclose and personal campaign because you get to actually be with so many of the voters," she said. "We both miss that."

And she said that despite the lack of privacy that comes with being first lady - a title she finds "too artificial" - she doesn't feel as if she must constantly bite her tongue to keep her opinions to herself.

"I'm actually very disciplined," she said. "I don't really have to watch everything I say because I'm pretty well-behaved."

At Limerick Elementary School in Canoga Park, Calif., on Wednesday where she was promoting reading, Mrs. Bush said it appears that Sen. John Kerry will be the Democratic presidential nominee. "I assume he will be," she said.

"They've had a big primary," she said about the Democratic candidates. "They've spent $100 million dollars - all of them together - campaigning around the United States running ads. In general, I think they campaigned against my husband rather than each other."