By James Coomarasamy
BBC News, Washington
The former Governor of New York, Mario Cuomo, once said: "You campaign in poetry. You govern in prose".
The Capitol steps - where the inauguration ceremony will take place
Inauguration Day marks the intersection of the poetic and prosaic - an occasion that mixes ceremony and rhetoric, with a changing of tenants at 1600 Pennsylvania Avenue.
The key moment is noon, when the baton is officially passed from one US President to the next.
On the steps of the Capitol building, Chief Justice John Roberts, whose tenure outlasts that of the president who appointed him - George W Bush - will administer the oath of office.
With one hand on the bible used at Abraham Lincoln's 1861 inauguration, but not since, Barack Obama will swear to preserve, protect and defend the US Constitution to the best of his ability.
He will then look out over the crowds thronging the Mall, with the Washington Monument and Lincoln Memorial in the distance, and deliver one of the most eagerly anticipated inaugural addresses in history.
According to the president-elect's advisors, the speech will last just over 15 minutes and have as its twin themes the restoration of public confidence and personal responsibility.
Mr Obama will attend 10 inaugural balls on Tuesday evening
The parallels with John F Kennedy's 1961 call to "ask not what your country can do for you, but what you can do for your country" seem greater than ever.
Before all of this, the new Vice-President, Joe Biden, will be sworn in, singer Aretha Franklin will perform and - in one of the most controversial parts of the ceremony - Rick Warren, the Southern Baptist Pastor of the Saddleback Mega Church, will give the invocation.
His socially conservative views - in particular, his outspoken opposition to gay marriage - have caused a great deal of discomfort among some of Mr Obama's supporters.
Rick Warren will not steal the new president's thunder, but there will be an unusual amount of attention paid to the words he chooses to mark the occasion.
After the ceremony, the new occupant of the White House will wave goodbye to his predecessor, before joining the new Vice-President and congressional leaders to feast on pheasant and duck at the traditional inaugural lunch.
Following that, there will be the inaugural parade and a long, long night of ball-going for the new First Couple.
Their presence - and their dance steps - are awaited at ten separate functions.
While all this is happening, others will be getting down to work.
Once the Bushes and Obamas have set off in the morning to attend the official ceremonies, removal vans will get into position next to the White House.
After months of planning, Obama staffers will begin unloading the new tenant's personal items (as well as those of the 44th president's live-in mother-in-law, presumably).
Ever punctual, the Bushes shipped most of their possessions to their ranch in Crawford, Texas, last summer.
It will not just be manual labour, though.
As soon as the exchange of power has taken place on the Capitol steps, some members of the incoming administration will clock in for work at their new surroundings, their in-trays already overflowing.
The transition will officially be over.
And the Obama presidency - with all its challenges and expectations - will have officially begun.