The presidential campaigns of President Bush (search) and John Kerry (search) were roiled by a series of events Friday as a new FOX News/Opinion Dynamics poll showed that the president still has a lead over his Democratic challenger, 50 percent to 45 percent.

Also Friday, a new video purporting to be from Usama bin Laden (search) was aired by Arabic satellite station Al-Jazeera, where the Al Qaeda leader directly admitted for the first time that he carried out the Sept. 11 attacks and promised to lay out "the best way to avoid another Manhattan." He said the 2001 attacks would have been less severe if Bush had been more alert.

Click here for Friday's edition of FOXNews.com's daily campaign digest, Trail Tales.

It was the first footage of the terrorist mastermind to surface in more than a year. Multiple sources told FOX News that the 18-minute long videotape was authentic. No one has yet indicated that the national terror threat level would be raised.

The Bush administration said it believed the tape was authentic.

"Let me make this very clear: Americans will not be intimidated or influenced by an enemy of our country," the president said in Toledo before getting back aboard Air Force One. "I'm sure Sen. Kerry agrees with this. I also want to say to the American people that we are at war with these terrorists, and I am confident that we will prevail."

Kerry also made some brief comments about the bin Laden video.

"As Americans, we are absolutely united in our determination to hunt down and destroy Usama bin Laden and the terrorists," Kerry said as he boarded a campaign plane in West Palm Beach, Fla. "They're barbarians and I will stop at absolutely nothing to hunt down, capture or kill the terrorists wherever they are, whatever it takes, period."

Republicans have insinuated that terrorists would like to see Kerry in office over Bush, since they charge the Massachusetts senator would be too soft in the War on Terror.

"This almost looks like an endorsement from Usama bin Laden for John Kerry," said David Johnson, former campaign manager for Bob Dole.

But Alan Colmes, co-host of FOX News' "Hannity and Colmes," said, "I don't think he's [bin Laden] there with a Kerry-Edwards sticker in the cave ... I think he'd like to feel he can have an effect."

While Johnson said it's too early to determine what impact — if any — the bin Laden tape will have on the election, "it helps President Bush because in the War on Terrorism, the American people are more comfortable with him."

"We're in a global war against international terrorism ... it's going to take a long while and there's going to be some setbacks in the way before we achieve final victory over Usama bin Laden."

Explosive Ammunition

The other hot-button issue that continued to heat up on Friday was that of the missing cache of explosives that disappeared from the Al-Qaqaa (search) munitions base in Iraq.

The Massachusetts senator has charged the president with dereliction of his duty as commander in chief and not owning up to the alleged blunder while Bush has accused Kerry of being willing to "say anything" to get elected by using the issue on the campaign trail. Republicans have said that Kerry's use of the murky issue signaled that he had nothing else on his own record to talk about in the last week of campaigning.

Both candidates' comments on this issue on Friday, however, were muted in comparison to their back-and-forth blasts over it throughout the week.

After four days of tough attacks on Bush over missing explosives in Iraq, Kerry said the election offered a fundamental choice. "Do you want four more years of the same failed course?" he asked voters in pivotal Florida, the state where the race was decided four years ago. "Or do you want a fresh start for America that takes us in the right direction?"

Bush returned to the central theme of his campaign, that he is a stronger leader than Kerry and would do a better job of protecting the country.

"I've learned firsthand how hard it is to send young men and women into battle, even when the cause is right," the president said in New Hampshire, the only northeastern state he carried four years ago — and where he is trailing now, according to a new poll.

"The issues vary. The challenges are different every day. The polls go up. The polls go down. But a president's convictions must be consistent and true," Bush said. He did not even mention Kerry in his first speech in Manchester, N.H., but brought up his opponent at the next stop, in Portsmouth.

A spate of new state polls reflected the tightness of the race. The race is essentially tied in Wisconsin, which narrowly voted Democratic four years ago.

Reports of an estimated 377 tons of explosive ammunition that disappeared from a munitions depot have proved to be a lightning rod in this year's presidential election. But questions continue to surface regarding exactly how much, and when, the ammunition went missing as the original story began to shred.

On Friday, the Pentagon put forth a U.S. soldier who said he actually led efforts to remove and destroy about 250 tons of material from the facility.

In New Hampshire, demonstrators at the Bush rally held up signs that spelled out "360 TONS." Bush backers shouted them down with chants of "four more years!" and the president's supporters ripped the placards from the protesters' hands.

New videotape released Friday added even more fuel to the fire.

Footage shot by a Minnesota television crew traveling with U.S. troops in Iraq when they first opened the bunkers at Al-Qaqaa — nine days after the fall of Saddam Hussein — shows what appeared to be high explosives still in barrels and bearing the markings of the International Atomic Energy Agency.

The video taken by KSTP of St. Paul on April 18, 2003, could reinforce suggestions that tons of explosives missing from that location were looted after U.S. troops entered the country.

The Pentagon also declassified and released a single image, taken by reconnaissance aircraft or satellite just days before the war, showing two trucks outside one of the dozens of storage bunkers at Al-Qaqaa.

Kerry running mate John Edwards said the missing cache and the FBI investigation into Halliburton's contracts in Iraq prove that new leadership is needed in the White House.

"They've been incompetent in Iraq, and here at home they always look out for their powerful friends at the top," the Democratic vice presidential candidate said at a campaign stop in La Crosse, Wis.

Wanted: New Direction or Experience?

Throughout the day, Bush and Kerry were setting up the race for the White House as one between tested experience and a fresh start.

Clear majorities of both Bush and Kerry supporters say they definitely plan to vote for their candidate, and the number saying they may change their mind is now fewer than one in 10, according to the poll released Friday. One source of the president’s advantage is the War on Terror — more than twice as many voters say Bush is the candidate who would more aggressively fight terrorism.

Bush's five-point lead is down from a seven-point lead last week, when he had a 49 percent to 42 percent edge. The number backing independent candidate Ralph Nader is now less than one percent. Bush’s lead is within the poll’s margin of error of plus or minus three percentage points.

The rivals were revisiting tightly contested states Friday, with the president heading to New Hampshire and Ohio and his Democratic challenger looking to rally Florida voters.

In Manchester, N.H., on Friday, Bush focused on his leadership in a post-Sept. 11 world, saying the U.S. strategy for winning the War on Terror is working.

"Freedom is on the march and America and the world are more secure. Our strategy to win the war is succeeding," Bush said at a rally. "The terrorists are on the run. So long as I am your president, we will be determined and steadfast and we will keep the terrorists on the run."

"When a president speaks, he must speak clearly and he must mean what he says," Bush told supporters. "I meant what I said and the Taliban regime in Afghanistan doubted our commitment — the regime is no more and America and the world are safer."

Simultaneously, in Orlando, Fla., Kerry urged supporters to cast their ballots on Nov. 2 for the candidate who can steer America in a new direction.

"Four days from now, Americans will face a choice. How will we find our way forward? How will we keep America safe, and keep the American dream alive? I believe we begin by giving this country we love a fresh start," Kerry said, before laying out what he called his "summary" of his case on "how, together, we can change America."

Later, in Orlando, Kerry said Bush "just doesn't understand the problems facing America" and urged Floridians to "walk out of here and vote," a reference to early voting allowed in the crucial battleground state. The senator also renewed his contention that Bush diverted attention from the real threats of Al Qaeda and Usama bin Laden by going to war in Iraq.

Bush was campaigning in Ohio Friday afternoon with actor-politician Arnold Schwarzenegger.

Organizing a big finish, Bush planned election-eve rallies in Ohio, Pennsylvania, Wisconsin, Iowa, New Mexico and Texas, the White House said. Kerry's tentative plans for Monday call for stops in Wisconsin, Michigan and Ohio. Looking beyond the election, the president was planning a Cabinet meeting on Thursday.

After scalding Kerry earlier this week as weak and wavering, Bush told a rally in Portsmouth, Maine, "I'm sure Senator Kerry means well but his policies are the wrong policies at this time of threat."

Kerry appealed for Jewish support in Florida, saying he has been a reliable friend of Israel. "I have never wavered on one vote, on one resolution, on one issue," he said.

A University of New Hampshire poll gives Kerry a four-point lead in New Hampshire, after polls earlier this month put the president up by five.

In a thinly veiled slap at his Democratic opponent — who has been accused by the GOP and others as being a flip-flopper on the war and other issues — Bush said if re-elected, he would never waiver when it comes to America's security.

"In any war, there are good days and bad days, but on any day, you need the same resolve," Bush said during the Manchester rally, adding that as president, people "notice your shortcomings."

"Sometimes I'm a little too blunt — I get that from my mother. Sometimes I mangle the English language, I get that from my dad," the president said to thunderous applause and cheers. "In all the times, you know where I stand, what I believe and where I'm going to lead this country."

Bush was traveling with relatives of some of the heroes of Sept. 11, including the father of Todd Beamer, who was involved in bringing down United Flight 93, which crashed into a field in rural Pennsylvania.

"The president is playing defense today. He's going to be in the two states that he's carried in 2000 that he's been running behind in," said FOX News' political contributor Michael Barone.

Bush went from Manchester to Portsmouth, which is near the border of Maine, which Al Gore carried in 2000, then headed to Toledo and Columbus, Ohio.

"If he doesn't carry Ohio and all the other states go the same way [as they did in 2000], he's got 258 [electoral] votes and that's a losing total," Barone said.

California Gov. Arnold Schwarzenegger appeared with Bush, hoping to provide some extra muscle and tip the Ohio tally in the incumbent's favor. The president was supposed to be introduced by Boston Red Sox pitcher Curt Schilling at one campaign stop Friday, but the White House later said doctors ordered Schilling not to travel, presumably because of the hurt ankle he suffered during the American League Championship Series against the New York Yankees.

Kerry will get more help from rock star Bruce Springsteen, who was expected to back him at a "Fresh Start for America" rally in Miami Friday evening.

The Massachusetts senator on Friday was enumerating what his campaign has called "a series of wrong choices" made by Bush on Iraq, the economy, health care and other issues. Campaign staffers say their candidate may also mention the controversial issue of missing ammunition in Iraq on Friday as part of his final argument challenging Bush's ability to perform as commander in chief.

"John Kerry is playing offense today," Barone said, noting that Kerry will be hitting important regions of the Sunshine State — Orlando, West Palm Beach and Miami.

"I think he's going there to shore up his support among Jewish Americans," Barone said, noting that Gore and his running mate, Joe Lieberman, in 2000 received big margins in Florida among Jewish voters. "That's one of the reasons the election was so close," Barone said, but noted that Bush is making inroads with that community, with the help of former New York City Mayor Ed Koch, a Democrat.

Aloha, Hawaii

For his part, Cheney on Sunday night will rally voters in Hawaii where just two Republicans have ever won the state in a presidential race. The Bush-Cheney campaign says Hawaii is within reach and that its four electoral cotes are worth fighting for in an election where every vote will count.

"We are competitive in the state; this is a very close race," said Cheney spokeswoman Anne Womack.

Hawaii may prove to be a surprise on Election Day; polls there show the candidates neck and neck, even though Al Gore won the state in 2000 by 18 percentage points.

Kerry's daughter, Alexandra, and Al Gore were also campaigning in Hawaii on Friday.

"I think Hawaii is seriously in play for the Republicans," Barone said, noting that polls show that Japanese Americans and Filipino Americans in the Aloha State are voting for Bush even though they vote heavily democratic in state election.

Hawaii has two characteristics when it comes to elections, he said. "First it votes for Democrats, second, it tends to vote for incumbent presidents of both parties."

FOX News' Wendell Goler, Molly Henneberg and The Associated Press contributed to this report.