Both major U.S. presidential candidates and their running mates reacted Monday to the financial turmoil on Wall Street in the wake of the bankruptcy announcement from the investment bank Lehman Brothers. Barack Obama and John McCain have both promised to reform federal regulatory bodies to prevent another series of bank failures. As VOA National correspondent Jim Malone reports from Washington, the problems in the U.S. financial sector have refocused attention on the economy as the biggest issue in the presidential campaign.

Democratic candidate Barack Obama campaigned in Colorado and described the situation on Wall Street as the most serious financial crisis since the Great Depression of the 1930s.

Obama blamed the current crisis on eight years of Bush administration policies that he said have shredded consumer protections and weakened government oversight.

"Now, instead of prosperity trickling down, the pain has trickled up from the struggles of hard working Americans on Main Street to the largest firms on Wall Street," he said. "This country cannot afford four more years of this failed philosophy."

Obama's Republican opponent, Senator John McCain, held campaign rallies in Florida.

McCain promised that he would replace what he called the outdated patchwork quilt of financial regulatory oversight with a new system that is more transparent.

"People are frightened by these events," he said. "Our economy, I think, still, the fundamentals of our economy are strong. But these are very, very difficult times."

Democrats, however, seized on McCain's comment that the fundamentals of the economy remain strong, especially in light of public opinion polls that have shown economic issues are the top concerns for voters this year.

At a rally later in the day in Florida, McCain changed his comments.

McCain said he believes the country is in an economic crisis and he vowed to clean up the greed and corruption on Wall Street.

"People tonight will be sitting around the kitchen table trying to figure out how they are going to stay in their homes, how they are going to keep their job, how they are going to put food on the table, and America is in a crisis today," he said.

Senator Obama said Senator McCain's initial positive comments on the economy show he is out of touch with the economic concerns of most Americans.

"Why else would he say that we have made great progress economically under George Bush. We just woke up to news of financial disaster, and this morning he said that the fundamentals of the economy are still strong," he said.

Obama's vice presidential running mate, Senator Joe Biden, also weighed in.

Biden told a crowd in Michigan that Senator McCain's economic plan would continue the approach of the past eight years under President Bush.

Meanwhile, McCain's vice presidential running mate, Alaska Governor Sarah Palin, campaigned in Colorado and said she and McCain would fight to keep taxes low as the best way to grow the economy.

Palin has so far overshadowed Biden in the battle of vice presidential candidates. Biden brings years of foreign policy experience to the Democratic ticket, but Palin has excited social conservatives within the Republican Party and is demonstrating appeal to a broader cross-section of women voters as well.