Sen. Barack Obama speaks at a rally at Fifth Third Field in Dayton, Ohio, 09 Oct. 2008

U.S. presidential candidates Barack Obama and John McCain continue to focus on the economy, as they campaign in crucial states less than a month before the election.

Obama, addressing supporters in Dayton, Ohio, blamed the economic crisis on "greed and irresponsibility" on Wall Street and predicted that recovery will be a long process.

At the rally Thursday, the Democratic Party senator from Illinois said the government should crack down on what he called "predatory lenders."  He said mortgage fraud should be treated like a crime, and that taxpayers should be able to get a share of the benefits when the market recovers.

McCain, a Republican, and his vice presidential nominee, Alaska Governor Sarah Palin, are campaigning in the state of Wisconsin. 

Sen. John McCain shakes hands with a supporter during a rally at the Center Court Sports Complex in Waukesha, Wisconsin, 09 Oct. 2008

McCain told a rally that Americans are facing the greatest financial crisis of their lifetime.  He said the heart of the financial meltdown - the housing crisis - needs to be addressed.  He highlighted his plan to have the federal government buy up bad mortgages and replace them with manageable loans.

The veteran Arizona lawmaker also pledged to impose a spending freeze to stop what he called the "spending spree in Washington."

Meanwhile, the latest Gallup poll has Obama leading McCain - 52 percent to 41 percent.

In other news, President George Bush signed an executive order establishing a team to help the winner of the November 4 election transition to the White House in January. 

Some information for this report was provided by AP and Reuters.