After a divisive presidential election and months of late-night jokes about syntax slip-ups and questionable quotes, Sept. 11 transformed President Bush's presidency from dependence on half a nation's good sportsmanship to chart-topping popularity and wide-ranging support.

Since White House Chief of Staff Andrew Card whispered in the president's ear that "America is under attack" during a book reading with elementary school children in Florida, Bush has been on a trajectory rarely seen by most leaders.

"It has given the president a special mission, a special opportunity that comes to few presidents," said Stephen Hess, a presidential analyst who worked in the Eisenhower and Nixon White Houses. "You can compare him to poor Bill Clinton, who hungered for a legacy more than any other [president], but never got an opportunity."

Unabashedly, White House officials point to America's greatest wartime presidents -- Abraham Lincoln and Franklin D. Roosevelt -- as well as the Vietnam-scarred Johnson presidency to put Bush's mission in historical context.

"Every president has an agenda, but they are always subject to the whims of history," senior adviser Karl Rove said. "The times place demands on them; they give them war, recession and strife -- or they give them quietude."

"This is what history's given him," Rove said.

Bush has taken the historical opportunity to move from the image of a man who some said couldn't lead a horse to water to a wartime leader with popularity ratings that peaked at 91 percent shortly after Sept. 11.

The momentum has personally changed the president as well. He has matured, gained his confidence, and articulated his role as protector of the nation.  And he has used those assets to alter inexorably the entire U.S. government.

"War changes everyone involved," said Ron Kaufman, political director for Bush's father. "It changes not your values, but what you value. People call it maturity, but it's something deeper than that. You're dealing with life and death every day."

The president has also become more fatalistic about his own life, those near him have said.

Reminded recently that assassination is a constant threat, Bush shrugged his shoulders and said, "It's not my job to worry about it."

"The events, I suppose, have hardened him," said Joe Allbaugh, director of the Federal Emergency Management Agency and a longtime Bush associate.

The president has also sought a disciplined outlet for a stressful and unending job -- running.  Though always an avid runner, the president said his three-mile distances are faster now, perhaps an indication of the focus on extraordinary challenges ahead of him.  

The changes first became evident just 12 hours after the attacks and moments before his address to the nation about America's response to the worst terror attack in history.

In a cramped nuclear shelter deep beneath the White House, Bush told his national security team: "Get the troops ready. This is a time for self defense.  This is our time." 

With those words, a war against terrorism began, and so did absolute changes in presidential leadership. New presidential powers were sought, an overhaul of the federal government began, and Congress enacted new laws to help enforcement officials bring to justice an invisible enemy that had previously been underestimated. 

Of course, not everyone is charmed by the deliberate manner laced with easygoing humor and steely resolve that the president now emotes.

Critics call the president arrogrant for maintaining a level of secrecy in the executive branch that previously had been whittled down. They say his go-it-alone style is alienating allies and that he is lazy for handing out chores like education reform policy.

"We've all given Bush a pass because we want to believe he's up to the job," said former Clinton White House adviser Paul Begala. "It scares us to think he's not."

His staff, however, defends the president's methods and explains them in the context of what he is up against.

"He had to delegate issues that might have risen to him that now can be managed by others," Card said.

But among those the president has taken full charge of: getting a Department of Homeland Security -- with 170,000 employees from 22 agencies -- passed through Congress; proposing new "first strike" powers for the U.S. military; dramatically increasing law enforcement powers; and forging new alliances with nations that previously were of borderline interest to the United States.

In the 2000 campaign Bush, a foreign policy novice, couldn't name the president of Pakistan. Now, Gen. Pervez Musharraf is an ally.

He has also turned from his opposition to "nation-building" to promising to get Afghanistan on its feet, and has helped build Russian-U.S. relations to the warmest point ever.

Some concerns still plague the country -- particularly a growing budget deficit that has trimmed economic forecasts for the next 10 years and beyond.

"The era of 'big government is over' is over," said Begala, using a term coined by his former boss, Clinton.

Others issues -- altering Social Security, improving prescription drug coverage, reforming election laws and expanding the role of religion in government services -- have altogether fallen by the way side since Sept. 11.

Falling markets and rash of corporate abuses have given Democrats an opening for political attack before November's midterm elections.

That reality has forced the president to continue on a fund-raising track.  But while November's outcome is uncertain, in this post-attack era, Bush's speeches combine reassuring words with the occasional tears and thanks for audience members' prayers.

The Associated Press contributed to this report.