* Official swearing-in will take place the previous day
* Crowd expected to be about half the 1.8 million in 2009
By Mark Felsenthal
WASHINGTON, Dec 13 (Reuters) - President Barack Obama's second inauguration promises to be a more modest and less glitzy affair than his first.
When Obama stands on the steps of the U.S. Capitol on Jan. 21, the event will likely fail to match the grandeur and enthusiasm of four years earlier when he was sworn in as the nation's first black president, in what was seen as a new chapter after an era of unpopular wars and economic crisis.
This time around, the crowds are expected to be smaller, the inaugural balls less glittery, and the mood tempered by a first term that failed to deliver on the promise of a smooth return to economic prosperity and a harmoniously bipartisan Washington.
On top of that, Obama's swearing-in on Monday will have little real meaning - at least in a legal sense.
In a twist of the political calendar, the president will have officially taken the oath of office a day earlier.
That's because the law requires a president to be sworn in on Jan. 20, but in 2013 that date falls on a Sunday, meaning Obama will officially swear in at a low-key ceremony in the White House that day before the public event on Monday.
"A lot of the euphoria from four years ago has subsided and you've got a reduced sense of what's possible," said Greg Valliere, chief political strategist for Potomac Research Group.
In a shift for Obama, his inauguration committee is accepting corporate donations to help fund the traditional parade and other events after tapped-out Democratic donors spent huge sums helping him get elected.
Obama did not accept corporate donations for his first inauguration in January 2009.
Even as workers rushed to complete temporary grandstands on the street in front of the White House, the prospect that Sunday's ceremony might be shielded from public view raised complaints from the media. But an aide said on Thursday the official swearing in would be open to media coverage.
RETAKING THE OATH
Neither the smaller official ceremony, nor the re-run of Obama's second inaugural, should detract from the symbolic importance of the day, said Gil Troy, a historian at McGill University in Montreal.
Washington municipal authorities are planning for roughly half of the record breaking 1.8 million visitors who flocked to the nation's capital for Obama's first inauguration in 2009.
But with its full slate of celebrity-studded parties, its gathering of the political elite and a parade down Pennsylvania Avenue, it is the closest the United States comes to a coronation, said Troy.
"You're using all the props available to you," he said. "There is a tremendous series of historical associations. You're in the pantheon, and the entire country stops and looks at you."
Numerous presidents have had to retake the oath of office before, four of them because Inauguration Day fell on a Sunday.
Four years ago, Chief Justice of the Supreme Court John Roberts stumbled over the words of the swearing-in oath at Obama's inauguration.
After first saying a do-over would be unnecessary, the White House quietly arranged a second swearing-in to quash any questions about Obama's legitimacy as commander in chief.
In the White House's Map Room the next day, the new president stood with Roberts and several aides. After briefly chatting with a small group of assembled journalists, the president faced the chief justice.
"Are you ready to take the oath?" Roberts asked.
"I am," Obama replied. "And we're going to do it very slowly," he joked. (Additional reporting by Matt Spetalnick; editing by Alistair Bell and Todd Eastham)