Barack Obama took dead aim at John McCain 's economic philosophy Tuesday, charging that the Republican presidential candidate would extend Bush administration policies that helped foster Wall Street's turmoil, while McCain proposed creating a blue-ribbon commission to study the nation's deepening financial crisis.

US presidential nominees Senator John McCain (L) and Senator Barack Obama (R) are shown in this combination of file photographs from campaign stops from July 18, 2008 in Warren Michigan (McCain) and August 4, 2008 (Obama) in Lansing, Michigan. [Agencies]

The candidates dueled as the financial world struggled to recover from the Wall Street shocks of Monday, when the collapse of Lehman Brothers and the sale of Merrill Lynch to Bank of America sent markets reeling and raised new fears of recession.

The upheaval, combined with the recent government takeover of mortgage giants Fannie Mae and Freddie Mac , stirred the US presidential campaigns. Democratic nominee Obama detailed his remedies Tuesday in a speech in Colorado , while McCain spoke in Tampa, Fla. Texts of both speeches were made available in Washington .

In some ways, the candidates sounded alike.

"Too many firms on Wall Street have been able to count on casual oversight by regulatory agencies in Washington ," McCain charged.

"When regulators are chosen for their disdain for regulation and we gut their ability to enforce the law," Obama said, "then the interests of the American people are not protected."

They also agreed that regulators are hamstrung by outmoded laws.

"Let me be clear," Obama said. "The American economy does not stand still, and neither should the rules that govern it."

That's right, McCain said, "These regulatory agencies were fine maybe in the 1930s," he said in a CNN interview Tuesday.

But there were two major areas of contrast: McCain wants a commission, and Obama blames Republicans for the current crisis.

"We have to have a 9/11 commission, and we have to fix this alphabet soup of regulatory agencies that's left over from the 1930s. We can come back from this," McCain said.

The 9/11 commission, headed by former New Jersey Gov. Tom Kean , a Republican, and former Indiana Rep. Lee Hamilton , a Democrat, studied the causes of the 2001 terrorist attack and offered a series of recommendations to help prevent another.

Obama scoffed at McCain's idea.

"Senator McCain offered up the oldest Washington stunt in the book: You pass the buck to a commission to study the problem," Obama said. "But here's the thing: This isn't 9/11. We know how we got into this mess. What we need now is leadership that gets us out. I'll provide it; John McCain won't."