A culminating moment for Biden
Washington - Joe Biden, the talkative senator known for foreign policy expertise and a command of Washington's ways, is on the cusp of being the 47th vice president of the US.
On Tuesday morning, on the West Front of the Capitol, the 66-year-old Biden will raise his right hand and take the oath of office.
And so will mark one half of the transition of power, to be capped a short time later when Barack Obama takes his own oath before a dizzying crowd watching on site and around the globe.
Elections are not built around or decided by running mates, and given the enormity and the history of the moment surrounding Obama on Tuesday, Biden will remain second billing.
But his ascendancy to the vice presidency is a major turning point for the country too as Biden replaces Dick Cheney, who assumed huge powers under President George W Bush.
Cheney was a major voice on war and harsh interrogation techniques of suspected terrorists, and insists the Bush administration kept the nation safe; Biden accused him of doing more harm than any elected official in recent memory in "shredding the Constitution".
36 years as senator
All that will quickly be history, but Biden expects to play his own active role. The vice presidency is open to be shaped by the person in the job - and his boss. The most important role, of course, is that Biden assumes the presidency if Obama is unable to serve.
"This is a partnership," Biden said on Monday in a taping of The Oprah Winfrey Show.
"He's president of the United States, but as I said to him when he asked me, I said, 'Barack, don't ask me unless the reason you're asking me is you're asking me for my judgement," Biden said. "I get to be the last guy in the room when you make every important decision. You're president. Any decision you make, I will back."'
Biden ran for the presidency twice, in 1988 and in 2008, but never came close. He has served 36 years as a senator from Delaware, long establishing himself as a respected voice on foreign affairs and national security. He is well travelled and knows world leaders.
His wife, Jill, slipped on Winfrey's TV talk show by saying that her husband had been given a choice of being Obama's running mate or secretary of state; the latter nomination went to Hillary Rodham Clinton, Obama's main rival for the Democratic presidential nomination. A Biden spokesperson later said Obama only offered Biden the vice president's job.
A lawyer by trade, Biden won election to the Senate at a young age and has spent most of his life working there, but has still made a daily train commute home to Wilmington, Delaware.
Tendency to be long-winded
The vice presidency would seem to cap a career in which Biden is a Democratic Party elder and veteran of judicial nomination struggles, world crises and legislative dealmaking.
Born in working-class Scranton, Pennsylvania, Biden often speaks of a blue-collar work ethic. He did so on Sunday at a grand inaugural celebration concert at the Lincoln Memorial, when Biden said people deserve a chance to work hard, have dignity and show thanks to earlier generations.
Biden often takes a ribbing for his tendency to be long-winded and get himself into trouble with verbal gaffes. "Rhetorical flourishes" is the way Obama describes them.