President Bush and his Democratic Party challenger, John Kerry, campaigned in the critical, voter-rich states of Ohio and Florida two days before Americans go to the polls.
Both Mr. Bush, the Republican Party nominee, and Senator Kerry started their day attending Christian services - the president in Florida and Mr. Kerry in Ohio.
The senator told an African-American congregation that America's economic future depends on the outcome of Tuesday's vote, and that it is time to change course from the policies of the Bush administration.
"Countless numbers of people have lost jobs that have gone overseas. The jobs that replace them pay less than the jobs we are losing," he said. "That is the choice in this [presidential] race, my friends. It is a choice about what kind of country and society we are going to have. It is ultimately a choice about whether we are going to keep faith with the faith that we profess."
African-Americans are considered a vital component of the Democratic Party's base of support, but some public-opinion surveys suggest Mr. Bush is attracting a small, but significant, portion of the black vote, perhaps 15-to-20-percent. Kerry campaign strategists say they are counting on a large African-American turnout on Election Day, and that they expect blacks to vote in overwhelming numbers for Mr. Kerry.
Earlier, in an interview on the ABC television network, the Massachusetts senator condemned a recent videotaped message from al-Qaida leader Osama bin Laden. Mr. Kerry said he would lead a more effective war on terrorism than President Bush, and dismissed polls that give the president higher ratings on questions of national security.
President Bush is trying to reinforce his image as a principled, tenacious leader. Addressing supporters at a rally in Coconut Grove, Florida, Mr. Bush accused Senator Kerry of constantly changing positions on the war in Iraq.
"A president must not shift in the wind. A president has to make the tough decisions and stand by them. The roll of the president is not to follow the latest polls," he said. "The roll of the president is to lead based on principle and conviction and conscience. And that is how I will continue to lead this nation."
Mr. Bush also defended his economic record, noting that the U.S. economy is growing once again and jobs are being created. He said John Kerry's economic program would cause government spending to skyrocket.
Partisanship between Democrats and Republicans is expected to rise between now and Tuesday. Speaking on CBS's "Face the Nation" program, Republican Arizona Senator John McCain said the nation must not remain embittered after the election.
"On November 3, we better call a truce and stop this [partisanship] and sit down together, no matter who wins, and start talking about national unity and addressing these issues. I deplore this kind of bitterness and anger. The enemy is al-Qaida, not Democrats or Republicans," he said.
But unity may be hard to achieve if, as feared, election results are delayed by legal maneuverings. Both the Kerry and the Bush campaigns are hoping to win by a sufficiently large margin that legal challenges mounted in any given county of any given state do not delay the naming of a victor, whoever it may be.