NEW YORK — John McCain is a gambler by nature, and the bet he placed yesterday may be among the biggest of his political life.

The Republican presidential nominee is hoping that his abrupt decision to suspend campaigning, seek a delay of tomorrow's debate with Democrat Barack Obama and return to Washington to help prod negotiations over a financial rescue package will be seen as the kind of country-first, bipartisan leadership he believes Americans want.

What he risks, if things don't go as he hopes, is a judgment by voters that his move was a reckless act by an impetuous and struggling politician that hardened partisan lines in Washington at just the wrong moment and complicated efforts to deal with the biggest financial crisis in more than half a century.

McCain laid out his rationale in stark terms, saying that the economy is in crisis and that he does not believe the package now on the table in Washington can win enough votes to pass. "Americans across our country lament the fact that partisan divisions in Washington have prevented us from addressing our national challenges," he said here in New York. "Now is our chance to come together to prove that Washington is once again capable of leading this country."

Obama initially resisted McCain's call to join him and return to Washington. But hours later he was forced to capitulate when President Bush called him and asked him to participate in a White House meeting with congressional leaders and his GOP rival.

But while agreeing to go back to Washington, Obama insisted last night, as he had earlier in the day, that tomorrow's debate go ahead as scheduled.

"I believe that we should continue to have the debate," he told reporters in Florida, where he is preparing for it. "I think that it makes sense for us to present ourselves before the American people, to talk about the nature of the problems that we're having in our financial system, to talk about how it relates to our global standing in the world, what implications it has for our national security, how it relates to critical questions like the war in Iraq and Afghanistan."

Much now will depend on whether McCain can deliver results, whether there is a constructive role for him and Obama, or if they become a sideshow to the real negotiations. But Obama's course carries risks as well, if he looked as if he were standing on the sidelines while McCain pushed for intervention that could help avert further damage to the nation's economy.

At a minimum, voters were treated again to contrasting styles of leadership yesterday, with McCain willing to act boldly, if impulsively, to inject himself into the middle of delicate negotiations to force a solution, and Obama adopting a cooler approach designed to show calm in the midst of crisis while preferring to give long-distance encouragement to all parties in the talks.