* Official oath in private on Sunday
* Public swearing-in to be held Monday
* Less excitement than landmark 2009 event
* Mood tempered by economic and political woes
* Can politicians "bury the hatchet" for a day?
President Barack Obama will take the official oath of office in a small, private ceremony at the White House on Sunday, setting a more subdued tone for his second inauguration than his historic swearing-in four years ago.
Obama will still be sworn in publicly outside the U.S. Capitol on Monday with all the traditional pomp, but that event will be mostly for show.
Technically, Sunday is the only one that really counts according to the Constitution, which mandates that the president be sworn in on Jan. 20.
Compared to the momentous atmosphere of Obama's first inauguration, the mood will be different this time.
A bitter 2012 election fight, stubbornly high unemployment and fiscal showdowns - both past and still looming - have tempered the hope that Obama symbolized when he took office after sweeping to victory on a mantle of change as America's first black president.
This time the crowds are expected to be smaller and enthusiasm surrounding the event diminished.
"For a lot of people, this is kind of old hat," said Russell Riley, an expert on presidential rhetoric at the University of Virginia. "The newness and excitement around the president's first history-making inauguration has given way to time-worn political reality."
On Sunday, following a wreath-laying ceremony at Arlington National Cemetery, Obama will be sworn in at the White House at 11:55 a.m. EST (1655 GMT). That portion will be private - except for a limited media presence - with a small audience of mostly family members gathered in the Blue Room.
Obama repeats the procedure the next day in the customary ceremony on a giant platform overlooking the National Mall. Ronald Reagan in 1985 was the last president to take the oath twice to avoid holding Inauguration Day festivities on a Sunday.
Both times, Obama will be sworn in by Chief Justice John Roberts who, after flubbing the oath the first time in 2009, administered it to Obama again in the White House the day after his inauguration.
INAUGURAL ADDRESS IS CENTERPIECE
While second inaugural addresses rarely make history, Obama's speech on Monday will be the centerpiece of the celebration and a chance to lay out his vision for the next four years.
The audience is not expected to be as big as in 2009 when a record 1.8 million people crammed into the National Mall to witness the swearing-in, but turnout is projected at 600,000 to 800,000, with millions more watching on television.
Although Obama won re-election decisively in November and his public approval ratings have hovered above 50 percent, he will usher in his second term facing an array of daunting challenges.
Battles are brewing with Republicans over spending, taxes, the national debt limit, gun control and immigration reform, while overseas he has the tasks of winding down the war in Afghanistan and reining in Iran's nuclear ambitions.
This weekend, Obama found himself juggling inauguration preparations and his presidential duties, including briefings on the fate of Americans and others caught up in a deadly hostage siege at a gas plant in Algeria.
Obama will save specific policy proposals for his annual State of the Union speech before Congress on Feb. 12, and on Inauguration Day he will instead focus more on broad goals and loftier themes, aides say.
In his inaugural speech, Obama is expected to talk about the need for political compromise where possible - a nod to the divisive fights with the Republican-led House of Representatives over fiscal matters. That, however, will also remind Americans of his own failure to meet his promise to be a transformational leader who would fix a dysfunctional Washington.
"It'd be great if the inauguration were a unifying moment - though I honestly can't say it will be. But just maybe for a day they can bury the hatchet and celebrate an important day for American democracy," Brian Hurley, 57, a local salesman, said as he guided an out-of-town visitor outside the White House gates.
But mindful of just how low the Republicans' poll numbers have sunk, Obama may seize the opportunity to appeal to Americans to bring pressure to bear on their lawmakers.
With the public ceremony falling on the national holiday honoring slain civil rights leader Martin Luther King Jr., Obama will also have a chance to draw historic parallels. While taking the oath on Monday, he will place his left hand on two Bibles - one once owned by Abraham Lincoln and other by King.
Obama kicked off inauguration events on Saturday, rolling up his sleeves at a school renovation project as he joined in a nationwide day of community service to celebrate King's legacy.
Workers, meanwhile, were putting the finishing touches on viewing stands stretching along the parade route, security barriers were going up, and thousands of police and National Guard troops were being deployed around the city.
Sunday's events begin at 8 a.m. EST (1300 GMT) when Vice President Joe Biden is sworn in at a private ceremony at the Naval Observatory. The Obamas and Bidens will attend an evening inaugural reception at the National Building Museum.
On Monday, after the president's address, Obama and Biden will ride in the inaugural parade, returning to the White House in a motorcade. They likely will get out to walk part of the way, waving to the crowd and surrounded by Secret Service agents.
After seeing the rest of the parade from a viewing platform in front of the White House, the Obamas will attend two official inaugural balls - compared to the 10 that were held in 2009.