WASHINGTON-Hillary Rodham Clinton had the Democratic presidential campaign trail to herself, but the camp of vacationing rival Barack Obama challenged the former first lady on her claim to have landed in Bosnia 12 years ago under sniper fire. Clinton characterized the episode as a "misstatement" and a "minor blip."

Obama spokesman Tommy Vietor said in a written statement Monday that her story "joins a growing list of instances in which Senator Clinton has exaggerated her role in foreign and domestic policy-making."

Clinton spokesman Howard Wolfson countered that the Obama campaign was only raising the issue because "they have nothing positive to say about their candidate."

Presumptive Republican nominee Sen. John McCain, meanwhile, launched a weeklong fundraising swing through western states as he returned to the campaign after a trip to Iraq, other points in the Middle East and Europe.

The Arizona senator was using an event Tuesday in the Republican stronghold of Orange County in southern California to showcase his grasp of the country's economic troubles, and counter the notion that he is not up to the task of leading a nation on the brink of recession.

McCain has acknowledged in the past that he knows less about economics than he does about national security and foreign policy, and Democrats have seized on such remarks to argue that the Republican is a novice on bread-and-butter issues that voters care about most.

McCain said he wants to leave the door open to a wide array of proposals to address the turmoil in home financing.

"I will not play election-year politics with the housing crisis," McCain said in remarks prepared for delivery Tuesday to local business leaders south of Los Angeles. "I will evaluate everything in terms of whether it might be harmful or helpful to our effort to deal with the crisis we face now."

McCain seemed to suggest he would be open even to potential solutions that, perhaps, stray from the Republican party line, saying: "I will consider any and all proposals based on their cost and benefits" and "I will not allow dogma to override common sense."

But the small-government advocate and four-term Arizona senator also put restrictions on how far he was willing to go.

"I have always been committed to the principle that it is not the duty of government to bail out and reward those who act irresponsibly, whether they are big banks or small borrowers," McCain said. "Government assistance to the banking system should be based solely on preventing systemic risk that would endanger the entire financial system and the economy."

In the increasingly ugly Democratic campaign, Obama's machinery refused to allow the former first lady's Bosnia story to pass without getting in a dig.

During a speech about Iraq last week, she said of the March 1996 Bosnia trip: "I remember landing under sniper fire. There was supposed to be some kind of a greeting ceremony at the airport, but instead we just ran with our heads down to get into the vehicles to get to our base."

According to an AP story at the time, Clinton was placed under no extraordinary risks on that trip. One of her companions, the comedian Sinbad, told The Washington Post he had no recollection either of the threat or reality of gunfire.

The Obama campaign statement carried Internet links to a CBS news video taken from the Bosnia trip and posted on YouTube. It showed Clinton and her daughter, Chelsea, walking across the tarmac from a large cargo plane, smiling and waving, and stopping to shake hands with Bosnia's acting president and greet an 8-year-old girl.

When asked Monday about the New York senator's recounting of those events, Wolfson recalled Clinton's book, "Living History," in which she described a shortened welcoming ceremony at Tuzla Air Base, Bosnia-Herzegovina.

"Due to reports of snipers in the hills around the airstrip, we were forced to cut short an event on the tarmac with local children, though we did have time to meet them and their teachers and to learn how hard they had worked during the war to continue classes in any safe spot they could find," she wrote.

Wolfson said: "That is what she wrote in her book. That is what she has said many, many times and on one occasion she misspoke."

Asked about the issue during a meeting with the Philadelphia Daily News' editorial board on Monday, Clinton said she "misspoke."

"I went to 80 countries, you know. I gave contemporaneous accounts, I wrote about a lot of this in my book. You know, I think that, a minor blip, you know, if I said something that, you know, I say a lot of things, millions of words a day, so if I misspoke, that was just a misstatement," she said.

Clinton often cites the goodwill trip she took with her daughter and several celebrities as a part of her foreign policy experience, which she claims gives her an advantage over Obama.

Vietor questioned whether Clinton misspoke, saying her comments came in what appeared to be prepared remarks for the Iraq speech. His statement for the Obama campaign included a link to the speech on Clinton's campaign Web site with her account of running to the cars. Clinton's campaign said what is on the Web site is not the prepared text, but a transcript of her remarks, including comments before the speech in which she talked about the trip to Bosnia.

While Obama took time off in St. Thomas, the U.S. Virgin Islands, Clinton spoke to invited guests at the University of Pennsylvania in Philadelphia and called on the Bush administration to name an emergency working group on home mortgage foreclosures to find new ways to solve the U.S. housing crisis.

Obama's campaign announced a six-day "Road to Change" bus tour across Pennsylvania, which holds the next presidential primary contest on April 22. The tour was to begin on Friday. Polls show Clinton with a substantial lead there.

Obama leads the all-important overall delegate count with 1,620 to Clinton's 1,499. But neither candidate is likely to get enough delegates in the remaining primaries and caucuses to reach the 2,024 needed to win nomination at the party's convention in late August in Denver. That means they must rely on support from superdelegates, party officials and elected leaders who are free to vote for any candidate, to become the nominee.

On Monday, McCain spoke about Iraq to a crowd of veterans in Chula Vista, California, many of whom served in World War II. He declared that both his Democratic rivals were "naive" and "dead wrong" to want to withdraw from Iraq, saying that would produce "chaos and genocide."

To underscore his view of the stakes in Iraq, McCain referred to a recent audio tape from Osama bin Laden in which the al-Qaida leader urged followers to join the al-Qaida fight in Iraq and called the country "the greatest opportunity and the biggest task."

"For the first time, I have seen Osama bin Laden and General (David) Petraeus in agreement, and, that is, a central battleground in the battle against al-Qaida is in Iraq today. And that's what bin Laden was saying and that's what General Petraeus is saying and that's what I'm saying, my friends," McCain said. Petraeus is the top U.S. commander in Iraq.