Americans want, and deserve, a full investigation into reasons for the financial crisis.

There is a danger, though, because leading members of Congress could be embarrased by their close association with Fannie Mae and Freddie Mac, that an investigation will not happen, or will be downplayed.

While waiting for those hearings, it is illuminating to look back at some history — and quotes.

Some people did see trouble coming years ago. There were unheeded warnings about the risks associated with so many subprime mortgages. And the complex financial deals known as credit default options were labeled a "time bomb"by billionaire investor Warren Buffett. Buffett went on to call these Wall Street inventions "financial weapons of mass destruction."

As is understood now, Fannie Mae and Freddie Mac, with backing by the federal government, encouraged the dangerous expansion of subprime mortgages. This expansion was due partly to a laudable government goal of increasing home ownership in poor, urban communities. But mandated quotas to boost home ownership in this target area resulted in a lowering of loan standards.

Several attempts to increase oversight of Fannie Mae and Freddie Mac were rebuffed by members of the Senate, many of whom had close ties to the mortgage giants.

Over the past 10 years, Fannie Mae and Freddie Mac have spent $200 million on lobbying. Since 1990, the two government-sponsored companies also contributed $19.5 million to political campaigns. And all that money appears to have worked in keeping the government out of Fannie's and Freddie's increasingly risky business practices.

Now we're all paying the price.

Sen. John McCain was one of several senators backing legislation two years ago to increase regulation of Fannie Mae and Freddie Mac. Republican Sens. Chuck Hagel of Nebraska, John Sununu of New Hampshire and Elizabeth Dole of North Carolina took the lead in this effort. And despite McCain's lesser role, he was quoted in May 2006 as saying, "If Congress does not act, American taxpayers will continue to be exposed to the enormous risk that Fannie Mae and Freddie Mac pose to the housing market, the overall financial system, and the economy as a whole."

Democrats who controlled the Senate Banking Committee prevented these measures from coming to a vote.

In 2005, Alan Greenspan, then head of the Federal Reserve, told Congress that if Fannie Mae and Freddie Mac "continue to grow, continue to have the low capital that they have, continue to engage in the dynamic hedging of their portfolios, which they need to do for the interest rate aversion, they potentially create ever-growing potential systemic risk down the road."

Without changes, Greenspan added, "We are placing the total financial system of the future at risk."

Did Congress listen? No. It appears that too many senators were influenced by campaign donations and lobbying from Fannie Mae, Freddie Mac and the broader financial services sector.

Franklin Raines, former CEOof Fannie Mae, in charge during a massive accounting scandal and who took home $52million in compensation during his five years at FannieMae, said at one point, "We manage our political risk with the same intensity that we manage our credit and interest-rate risks."

Clearly his reference to managing political risks is connected to the money flowing from Fannie Mae to many members of Congress.

The Center for Responsive Politics reports that the top three recipients of Fannie and Freddie PAC money since 1989 are Democratic Sens. Chris Dodd, $165,400; Barack Obama $126,349; and John Kerry, $110,000.

Maxine Waters, D-Calif., at a 2003 hearing considering additional oversight for Fannie Mae and Freddie Mac, said, "We do not have a crisis at Freddie Mac, and in particular at Fannie Mae, under the outstanding leadership of Mr. Frank Raines."

Echoing that support for the status quo at the mortgage giants, Sen. Barney Frank, D-Mass., ranking Demo-crat on the Financial Services Committee, said at the time, "These two entities — Fannie Mae and Freddie Mac — are not facing any kind of financial crisis."

Frank now has some explaining to do.

One observer described the cozy relationship between the government-backed mortgage banks and Congress saying, "Blessed with the advantages of a government agency and a private company at the same time, Fannie and Freddie used their windfall profits to co-opt the politicians who were supposed to control them."

Another recent explanation worth considering came from former President Bill Clinton, who said in a recent interview with ABCthat congressional Democrats should bear the bulk of the blame for the government's role in the current financial crisis. Clinton faulted Democrats in Congress for "resisting any efforts by Republicans in the Congress, or by me when I was president, to put some standards and tighten up a little on Fannie Mae and Freddie Mac."

This crisis clearly is bigger than Fannie Mae and Freddie Mac, but by buying up billions of dollars of risky mortgages, these agencies were major enablers of the other players that brought about the crisis, including mortgage lenders, commercial banks and investment banks.

It's clear that more than a few people saw trouble coming, and yet Congress failed to do anything.

Nothing less than a 9/11 Commission-type investigation or televised Watergate-style hearings is warranted to find out how and why this happened — and determine who should shoulder most of the blame.