The poll, conducted Oct. 28-29, shows Bush has the support of 47 percent of likely voters, down from 50 percent on Oct. 27-28, while support for Kerry has remained at 45 percent. Independent Ralph Nader is favored by 1 percent in the latest poll.
It is unclear what impact the release of a new videotape from Usama bin Laden (search) has had on support for either candidate. Half of the 1,200 Americans sampled were polled before the new video from the Al Qaeda leader.
The poll also was conducted at the height of the flap over what happened to 377 tons of explosives from an Iraqi military facility around the time of the U.S.-war against Saddam Hussein (search) last year.
Bush's lead is well within the margin of error, which means the rivals are effectively running even, and among registered voters the two are tied at 46 percent.
While self-identified independents picked Bush over Kerry 44 percent to 41 percent, more Bush supporters said they were open to changing their minds — 12 percent to Kerry's 6 percent. Ninety-two percent of Kerry supporters said their votes were definite, whereas 87 percent of Bush voters said they couldn't be swayed.
Every Last Vote Counts
With just three days to go until Election Day, both the Republican incumbent and his Democratic challenger are making their closing arguments to the American people in one of the most divisive elections in recent history.
"The person that sits in the Oval Office will determine the outcome of the War on Terror and the economy," Bush told supporters in Grand Rapids, Mich., on Saturday.
Bush also reminded voters of the Sept. 11 attacks. "Americans go to the polls at a time of war and ongoing threats unlike any we have faced before," he said.
The president did not mention the latest message from bin Laden, though ally Sen. John McCain (search), R-Ariz., said the videotape's release was "very helpful to the president." Polls have consistently shown Americans believe Bush is a more dependable leader in the War on Terror than Kerry.
Homeland Security officials said that the nation's terror alert would not be raised, while the administration warned state and local officials that the tape may be intended to promote or signal an attack on the United States.
For the second straight day, Kerry responded to bin Laden's re-emergence with his months-old criticism of Bush's post-Sept. 11 tactics in Afghanistan, the terrorist mastermind's once and perhaps current home.
"It was wrong to divert our forces from Afghanistan so that we could rush to war in Iraq without a plan to win the peace," said the Democratic challenger in Appleton, Wis. "It was wrong to outsource the job" of capturing bin Laden to local warlords.
But he was also careful to stress that the bin Laden tape should not be seized as a victory by either side.
"As Americans we are absolutely united, all of us. There are no Democrats, there are no Republicans," Kerry said. "As Americans we are united in our determination to destroy, capture, kill Usama bin Laden and all of the terrorists. They are barbarians, and we are going to hunt them down and we will make America safe."
Kerry repeated his pledge to "lead the world in fighting a smarter, more effective, tougher, more strategic war on terror.
Kerry spokesman Mike McCurry rejected Republican assertions that the Democrat was playing politics with the bin Laden tape.
Kerry has been trying to tap deep anti-war resentment within the ranks of the Democratic Party while assuring swing voters that he would keep them safe. He also pledged to provide "leadership and hope" to U.S. troops seeking a quick return home from Iraq.
"In three days, a woman or a husband is going to walk into that polling booth and they're going to think about their spouse that left to go to Iraq months ago, maybe close to a year ago," Kerry said. "And they're going to wonder how long that spouse is going to have to stay in Iraq, and the kids are going to be wondering, 'Daddy, Mommy, when are you coming home? Are you coming home?'"
At the close of the Appleton rally, Kerry handed out campaign literature to volunteers knocking on doors in the battleground state, and reminded voters about the end of daylight-saving time.
"Tonight you've got to remember to turn those clocks back one hour," he said. "If you don't turn them back one hour and you wind up not voting on Tuesday, George Bush is going to turn the clock back 30 years."
Click here for Saturday's edition of FOXNews.com's daily campaign digest, Trail Tales.
With up to 40 states already in the Kerry or Bush camps, the race is concentrated in Florida, Ohio, Pennsylvania, Wisconsin, Iowa, Minnesota, New Mexico and Nevada. Another six to 12 states could come into play before the campaigns draw to a close.
Throughout the battlegrounds, Kerry's mostly paid army of organizers were pitted against Bush's largely volunteer-driven team to get supporters to the polls Tuesday. It's too late for some: Early voting mushroomed this year and, in Florida alone, over 1.8 million voters have already cast ballots.
In Maine, a state Bush expects to lose to Kerry, the Democrat poured last-minute money into a Social Security ad aimed at elderly voters in the north. Unlike most states that have a winner-take-all system, Maine awards two of its four electoral votes based on congressional district votes.
Democrat Al Gore (search) stumped for Kerry in Hawaii, a state the former vice president won by nearly 20 percentage points in 2000. Polls showed the race much closer this year, and Gore donned a traditional Philippine shirt, a green-and-red flower lei and told Democrats, "The course of our nation can be determined by Hawaii's vote" — words not often spoken in presidential campaigns.
Vice President Dick Cheney (search) told Pennsylvania Republicans that the bin Laden tape is "a reminder that we are engaged in a global war on terror."
McCain, who has repeatedly campaigned on Bush's behalf, said the terrorists' videotape "focuses America's attention on the war on terrorism. I'm not sure if it was intentional or not, but I think it does have an effect," he said.
Campaigning in Marietta, Ohio, Kerry running mate Sen. John Edwards (search) put his skills as a courtroom orator to use.
In three days, "you're going to pull that curtain back. You're going to walk in. You're going to look down at the ballot and on one side of the ballot will be George Bush and Dick Cheney," Edwards said after asking supporters at a National Guard armory to picture themselves in the voting booths on Tuesday.
"Four more years of the same. But on the other side will be John Kerry and John Edwards. A fresh start for America," Edwards said
In a presidential race this close, both sides are on the alert for below-the-radar nastiness. Democrats said a bogus letter was circulating in South Carolina, threatening the arrest of voters who had outstanding parking tickets or failed to pay child support.
Bush used his final weekly radio address before Election Day to make a late appeal for votes, casting himself as the steady leader best equipped to fight terrorism.
"Even when you might not agree with me, you know where I stand, what I believe, and what I intend to do," Bush said on Saturday. "Soon, the decision will be in your hands. And however you decide, I urge you to get out and vote on Tuesday."
Kerry used the Democrats' last pre-election broadcast Saturday to promise he would repair the incumbent’s mistakes at home and abroad if elected president.
"In three days, you can choose a president who will defend this nation and fight for the middle class," he said. "And if you give me the chance, I will be that president."
Kerry also made an appeal to voters' domestic concerns.
"We can bring back good-paying jobs for middle-class families so that they don't just get by, they get ahead," he said.
On tap for Bush are stops in Ashwaubenon, Wis., and Minneapolis, Minn. After stumping up north, Bush will head to Orlando.
Kerry is scheduled to stump in Des Moines, Iowa, and Warren, Ohio.
FOX News' Carl Cameron, Julie Kirtz and The Associated Press contributed to this report.