The economy needs help and fast, Hillary Rodham Clinton declared Monday, claiming the experience for the job and saying the nation can't afford to break in a newcomer.

In speech that kicked off a two day campaign swing through Iowa, the New York senator painted a bleak picture of a U.S. economy battered by home foreclosures, rising oil prices and lack of good jobs for middle class workers.

The former first lady compared the situation to 1992, when her husband ran against the first President Bush.

"There seems to be a pattern here. It takes a Clinton to clean up after a Bush," she said to applause.

Without mentioning names, she suggested Democratic rival Barack Obama -- less than three years into his first term in the Senate -- and other candidates lack the experience necessary to address the nation's myriad fiscal challenges.

"There is one job we can't afford on-the-job training for -- our next president. That could be the costliest job training in history," Clinton said. "Every day spent learning the ropes is another day of rising costs, mounting deficits and growing anxiety for our families. And they cannot afford to keep waiting."

In Iowa, Obama was asked about Clinton's comments and offered a sharp response.

"My understanding is she wasn't Treasury secretary in the Clinton administration. I don't know exactly what experience she's claiming," he said. "Rather than just assert experience, if she has specific differences with me in regard to economic policy then let's have that debate."

The former first lady, speaking in a community gymnasium, outlined steps she said she would take to stem the housing crisis and help consumers in cold-weather states pay to heat their homes. Among other things, she said she would create a $1 billion fund for states to help homeowners who risk foreclosure.

She also addressed global challenges to the economy, including funds controlled by foreign governments to invest in U.S. stocks, real estate and businesses. She called for greater transparency for such funds, which are currently not required to disclose their assets or investment returns.

While she directed much of her criticism at the Bush administration and GOP presidential candidates, the subtext of Clinton's speech was clear: She has more detailed understanding of U.S. economic woes than her rivals.

She is seeking to reinforce that message after several days in which both Obama and Edwards stepped up their criticism of her past support for the North American Free Trade Agreement and other pacts that labor leaders have said were responsible for sending thousands of jobs out of the country.

Polls show Clinton locked in a tight race with Obama and Edwards in Iowa just over six weeks before the state holds its caucuses Jan. 3.

Her speech also tackled the issue of Social security.

In recent weeks, Clinton and Obama have traded barbs over the retirement program for seniors, which is forecast to run out of money around 2041 Presently, the first $97,500 in individual income is subject to the Social Security tax -- a level Obama has said must be increased in order to keep the program solvent.

Clinton has refused to say what she would do as president to preserve Social Security but has insisted such a tax increase would place an undue burden on middle class families.

She reiterated that point Monday, even suggesting that Social Security is not under imminent threat.

"We don't need more Republican scare tactics about a 'Social Security crisis,"' Clinton said. "And we don't need a trillion-dollar tax increase that will hit families already facing higher energy, health care and college costs. What we need is to focus on the real crises of health care and Medicare, and on expanding opportunities for poor, working and middle class families who are struggling now."

Clinton's campaign on Monday also began airing a new ad in New Hampshire and Iowa that confronts questions about her trustworthiness with a testimonial from a New York constituent whose son received a bone marrow transplant with the help of her Senate office.

The man, Joe Ward, says in the 30-second television spot that his family's insurance wouldn't cover the transplant. "We called Senator Clinton and asked for help," Ward says. "Her office called the next day letting us know the hospital was going to absorb the cost of the transplant. Now, her opponents are saying that Hillary can't be trusted. I trusted this woman to save my son's life. And she did."

The ad comes as polls show that one of Clinton's vulnerabilities is the public's view of her as insincere.