President Bush and Sen. John F. Kerry both sought political advantage Saturday from taped warnings by Osama bin Laden, jousting over how they would protect the country as they raced around the upper Midwest on the closing weekend of one of history's most bitter presidential campaigns.

The tape, which surfaced late Friday, introduced yet another uncertainty into the election calculus for both campaigns as they headed into a 72-hour sprint that they had thought would be dominated by more generic and traditional last-minute appeals to supporters to turn out at the polls.

Kerry attempted to stick to his strategy of criticizing Bush on economic and other domestic issues, and it was clear his aides did not want the tape to dominate the closing days of the campaign. Bush's advisers said the tape refocused attention on his strong suit and provided relief from a spate of troublesome news stories that beset him last week.

After an intense internal debate, the Bush administration announced in the afternoon that it was leaving the national terrorism threat level unchanged. But in a move that some Democrats branded as White House fear-mongering, the FBI and the Department of Homeland Security sent a bulletin late Friday to local and state officials warning them that the federal government "cannot discount the possibility that the video may be intended to promote violence or serve as a signal for an attack."

Echoing a signature line of his father's 1992 reelection campaign, Bush asked a crowd in an arena next to Lambeau Field, home of the Green Bay Packers, "In less than 72 hours, the American people will be voting, and the decision comes down to who do you trust?"

Kerry wants to close his campaign by focusing on the plight of the middle class. But at a morning rally in Appleton, Wis., the Massachusetts senator renewed his attack on Bush for letting bin Laden slip through his hands.

"As I have said for two years, now, when Osama bin Laden and al Qaeda were cornered in the mountains of Tora Bora, it was wrong to outsource the job of capturing them to Afghan warlords," Kerry said. "It was wrong to divert our forces from Afghanistan so we could rush to war with Iraq without a plan to win the peace."

Kerry had dropped the line after the tape aired Friday, but he reinserted it Saturday. In an emotional pitch to women and independents, Kerry said that when the spouses of service members deployed in Iraq go to the polls on Tuesday, "they're going to wonder whether or not we can afford four more years of a president who is unwilling to admit any mistake."

Bush reminded cheering supporters at a rally in Michigan -- a state that had looked safe for Kerry but became a final-weeks battleground -- that Americans will go to the polls "in a time of war and ongoing threats unlike any we have faced before."

"The terrorists who killed thousands of innocent people are still dangerous, and they are determined," Bush said in Grand Rapids. "The outcome of this election will set the direction of the war against terror."

Vice President Cheney was more explicit, telling a boisterous crowd in a high school gym in the eastern Pennsylvania town of Nazareth that the tape is "a reminder that we are in a global war on terror."

"It's a conflict we did not choose but one which we will win," Cheney said during a 45-minute speech with repeated references to Sept. 11, 2001.

Around lunchtime, the Bush-Cheney campaign sent its e-mail list of millions of supporters excerpts from two opinion articles praising Bush's handling of the tape's release on Friday and accusing Kerry of politicizing it.

In their final push, Bush and Kerry are shadowing each other around the same battlegrounds -- Ohio, which Bush won in 2000 but has been tough for him now because of job losses; Florida, which could again be the decisive state in a razor-thin election; and the Great Lakes region, where Bush has put Kerry on the defensive in Iowa, Minnesota and Wisconsin -- all won by Vice President Al Gore four years ago. Bush is also continuing to make aggressive runs in two Democratic strongholds, Michigan and Pennsylvania.

The election will be decided far from the bands and confetti and rhetoric. In the get-out-the-vote war, the Bush campaign claims the largest network of political volunteers in history and Democrats have deployed the largest-ever field of paid turnout workers.

The candidates are keeping an exhaustive pace to the end, with Bush planning a six-state, seven-rally schedule Monday. Bush spent Saturday night in Orlando. Kerry is heading back to Florida on Sunday -- and on Monday, in Cleveland, he meets up again with rocker Bruce Springsteen for a rally. Candidates traditionally lie low on Election Day, but Kerry plans to give satellite interviews to television stations in swing states. Bush is considering the same or perhaps making a campaign stop on the way back to Washington from his ranch in Texas. Making use of one of the perks of his office, Bush gave interviews in his Air Force One conference room to three Ohio television stations as he flew to Michigan on Saturday morning. Bush, a stickler for punctuality, kept the plane aloft an extra 15 minutes so that he could finish the sessions.

Bush, whose advisers had long hoped voters would have security not the economy on their minds as they went to the polls, presided over a classified videoconference about the bin Laden tape in his Columbus, Ohio, hotel suite before hitting the campaign trail for a four-state swing.

Hours after the security meeting, he bounded in shirt-sleeves into the DeVos Place arena in Grand Rapids, where his rostrum was flanked by red, white and blue shields promising "Four More Years of Integrity." Hanging from the wall and ceiling behind him was a fake Michigan license plate that read, "America: Safer Stronger Better."

The economy has been slower to recover and the situation in Iraq has remained more violent than Bush aides expected when they planned his campaign, so he has hung his bid on the more abstract issues of security and steadfastness.

"The role of the American president is not to follow the path of the latest polls," he said. "The role of the president is to lead based upon principle and conviction and conscience. Especially in dangerous times, mixed signals only confuse our friends and embolden our enemies."

Although Bush aides are more optimistic than they were last weekend, the race is still so tight that he continued his relentless attacks on his opponent, naming Kerry a dozen times in a 41-minute speech.

"I think it's fair to say, consistency is not his long suit," Bush said as the audience booed Kerry. "And next Tuesday, the American people will go to the polls. They will be voting for vision. They will be voting for consistency. They will be voting for conviction."

Kerry urged voters not to let the bin Laden tape divide them, while emphasizing that he would provide stronger military leadership.

"As Americans we are absolutely united, all of us. There are no Democrats, there are no Republicans," he said. "As Americans we are united in our determination to destroy, capture, kill Osama bin Laden and all of the terrorists. They are barbarians, and we are going to hunt them down, and we will make America safe."

While senior Kerry adviser Mike McCurry said that the Democrat is not retreating from his central position that Bush's choices have "let Osama wander the globe," it was apparent that the campaign wants to also keep focus on economic concerns.

Kerry went into a busy day of rallies in the battleground states of Iowa and Ohio, while running mate John Edwards also hit Ohio, as well as Maine and Florida. The men stuck to their central closing argument that the election is a stark choice between "four more years of the same" and "a fresh start" as they tried to energize middle-class voters looking for an economic boost.

Edwards also made a tailored appeal to young voters, a demographic that Democrats believe will help the ticket if turnout is higher than usual. "So many times in the history of America, it's taken young people to put us back on track," Edwards said.

Public opinion survey data show a close race -- statistical ties in key states and nationally, with slight but steady movement to Bush over the past week. That allows both sides to build cases that they are winning. White House senior adviser Karl Rove, who devised Bush's reelection strategy along with campaign manager Ken Mehlman, said Bush has "a clear lead" in the race for electoral votes.

"If you look at the upper Midwest -- Pennsylvania, Ohio, Michigan, Wisconsin and Minnesota -- in order for them to win, they need to take every one of them," Rove said. "For us to win, all we need is one. And we're going to take more than one. We are going to take at least two, maybe more."

Tad Devine, a Kerry senior adviser, predicted the senator will get at least 300 electoral votes -- 30 more than needed for victory.

Romano is traveling with Kerry. Staff writers Lyndsey Layton, with Cheney, and John Wagner, with Edwards, contributed to this report.

MINNEAPOLIS, 3:24 P.M. -- Bush has made gains among likely voters in the traditionally Democratic stronghold of Minnesota.DES MOINES, 3:18 P.M. -- Kerry rallied voters in the heartland, trying to secure Iowa's support, then took his message to Ohio.APPLETON, WIS., 11:46 A.M. -- At a Democratic rally, Sen. John F. Kerry criticized the incumbent, saying, "Osama bin Laden and al Qaeda were cornered. . . . It was wrong to divert our forces from Afghanistan so we could rush to war with Iraq."GRAND RAPIDS, MICH., 11:29 A.M. -- Recent Calvin College graduates, from left, Melissa DeWall, Nicole Robertson and Marcus Decker cheer on the message of President Bush's campaign.