Republican Sen. John McCain said he would suspend campaigning to help tackle a $700 billion bailout proposal and called on Democratic rival Sen. Barack Obama to postpone their debate Friday, as the roiling U.S. financial crisis took center stage in the presidential campaign.

Democrats dismissed the moves as political gimmickry, and Sen. Obama replied that the debate should go forward as planned. "Presidents are going to have to deal with more than one thing at a time...It's not necessary for us to think we can only do one...