Moments before Barack Obama takes the oath of office as President of the United States on Tuesday, January 20, 2009, former Senator Joe Biden will be sworn in as Vice President, succeeding Dick Cheney. The outgoing and incoming vice presidents are vastly different, personally, politically, and in their approach to the nation's second-highest job.

In the 2008 campaign, Democrat Joe Biden promised to be a very different vice president from Republican Dick Cheney.

"Vice President Cheney has been the most dangerous vice president we have had, probably in American history," said Joe Biden.

Throughout his eight years as George Bush's vice president, Dick Cheney has played a very active role. He not only advised the president, but some analysts say he had a strong influence on how policy was implemented.

"I would say he is not only the most powerful vice president but the most powerful person in modern American history who is not the president," said Barton Gellman.

Pulitzer Prize-winning reporter Barton Gellman, of the Washington Post, is the author of the book: Angler: The Cheney Vice Presidency.

"He was just plainly the dominant player on a wide range of issues, from the shape of the 2003 tax cut and the treatment of suspected terrorists, to the path to war, to the nomination of Supreme Court justices," he said. "But it is also important to understand that George Bush really was the decider."

But Cheney has said his role has been exaggerated by the media. Interviewed recently on Fox News Sunday, Cheney criticized Biden for saying he intends to scale back the powers of the vice presidency.

"If he [Biden] wants to diminish the office of Vice President, that is obviously his call," said Dick Cheney. "I think that President-elect Obama will decide what he wants in a vice president and apparently, from the way they are talking about it, he does not expect him to have as consequential a role as I have had during my time."

Kenneth Walsh, the chief White House correspondent for the magazine U.S. News and World Report, says he expects Biden to be an influential adviser as well, but not to be as independent as Cheney.

"Biden's argument is that he is going to try to get the vice presidency where it really should be - a supreme adviser to the president, but not a power center apart from other places in the government," said Kenneth Walsh.

The outgoing and incoming vice presidents could hardly be more different personally. While Biden is known for being very talkative, Washington-based national security analyst Anthony Cordesman says Cheney prefers to exert power behind the scenes.

"Senator Biden has never been someone who relied on a secretive, private set of relations, end-running, essentially, other people in the government or the political system," said Anthony Cordesman. "That was virtually the Cheney method of operating."

Walsh expects Biden to concentrate on advancing policies which will benefit the middle class, and to be a valued adviser to Barack Obama.

"He has been around Washington for more than 30 years," he said. "He has a tremendous portfolio - foreign policy, national security, judiciary issues. So I suspect that he is going to be much more in the mold that perhaps Walter Mondale was for Jimmy Carter - a very important adviser in the ways of Washington, but the president always being the 'decider,' as President Bush says."

While Joe Biden may not exercise as much power as Dick Cheney has, he is also unlikely to return to the traditional role of American vice presidents who had little to do but preside over the Senate and attend state funerals.