WASHINGTON — It is, as Abraham Lincoln said in his 1861 inaugural address, "a custom as old as the government itself," a peaceful transfer of power, an occasion of high hopes, a symbol of constancy in a changing world.
The tradition began in 1789 when George Washington hurriedly sent out for a Bible and added the words "so help me God" to the oath prescribed by the Constitution.
When George W. Bush repeats those words Saturday and becomes the 43rd president he will do so in a ceremony that is the principle rite of passage of American representative democracy.
Even those who plan to protest the election that brought Bush to power can be seen as part of what Washington, in the very first inaugural address, called "the sacred fire of liberty" and "the experiment entrusted to the hands of the American people."
When Bush's father was sworn in as the 41st president in 1989, he placed his hand on the Bible Washington had used and spoke of the "stunning fact" that the unbroken chain of the American presidency now stretched over two full centuries.
"We meet on democracy's front porch, a good place to talk as neighbors and friends," the elder Bush said as he looked out past the Washington Monument from the West front of the Capitol.
It was a day, he said, "when our nation is made whole, when our differences for a moment are suspended."
Inauguration Day often has been like that, a moment of celebration and continuity in often turbulent times.
People attending Lincoln's first inaugural in 1861 would long remember Sen. Stephen Douglas, one of his presidential rivals, smilingly reaching for Lincoln's hat when the new president could find no convenient place to rest it.
Yet Lincoln was shielded by a squadron of cavalry as he rode to the Capitol that day amid fears that an assassin might take his life before he had fairly begun.
Despite Lincoln's appeal to "the better angels of our nature," the storm clouds of civil war did not abate.
Historian Michael Beschloss, speaking at a recent conference on White House history, took note of inaugurations where relations were strained between the incoming and outgoing presidents.
John Adams, for example, used his appointment power to give federal judgeships to members of his political party, then left town and did not attend Thomas Jefferson's inauguration. Adams' son, John Quincy Adams, followed his father's example, and became "one of only two presidents in American history so disappointed by his defeat that he refused to attend his successor's swearing-in."
When Rutherford B. Hayes became president in 1877 after losing the popular vote and engineering a deal that gave him an Electoral College victory, some dubbed him "Rutherfraud."
"Emotions about Hayes' deal ran so high that as with Lincoln, people were worried that the new president might be murdered before he began," Beschloss said.
He noted that to sweeten the atmosphere, Hayes promised not to run for a second term.
On Inauguration Day, 1909, William Howard Taft took heart from the blizzard blanketing the city.
"It's my storm," Taft said. "I always said it would be a cold day when I got to be president of the United States."
The emotional atmosphere was icy when Franklin Delano Roosevelt rode to his inauguration with President Herbert Hoover in the midst of the Great Depression.
Thirty years later, relations between President Truman and President-elect Eisenhower were so frigid that Eisenhower refused to get out of the limousine when it arrived at the White House on the morning of his swearing in.
"Dramatic stories," said Beschloss. "But when you look at the whole of American history, what strikes you is how resilient is the process by which we transfer power from one presidency to the next."
There was a touch of frost last week when President Clinton told an audience that George W. Bush prevailed over Al Gore only because Republicans had acted "to stop the voting in Florida."
But Clinton made sure that Bush got off to a good start, providing briefings for his staff and meeting with Bush for 90 minutes.
"The American people, however divided they were in this election, overwhelmingly want us to build on that vital center without rancor and personal attack," Clinton said.
Most inaugural speeches are soon smothered by events. Only a few are etched in memory, like the arresting line from FDR's first inaugural: "The only thing we have to fear is fear itself."
The ceremony itself is widely viewed as an indicator of the next four years.
"The ceremonies have an air of dignity that is often reserved only for a monarch, yet at the same time reflect our down-to-earth feelings toward politicians," wrote the authors of the companion volume to the Smithsonian Institution's new interactive exhibit, "The American Presidency, a Glorious Burden."
"They are a call for national unity and an occasion for partisan gloating. Inaugurals are populist and elitist, public and private, inclusive and exclusive, commercial and civic. Most of all they reflect the hopes and aspirations we have for the American presidency and our democratic process."
Lawrence L. Knutson has covered the White House, Congress and Washington's history for more than 30 years.
On the Net: Joint Congressional Committee on Inaugural Ceremonies site: inaugural.senate.gov
Library of Congress: http://memory.loc.gov/ammem
National Archives and Records Administration: www.nara.gov/exhall/originals/inaugura.html
White House Historical Association: www.whitehousehistory.org