She never was the first lady, she was always the co-president

Gail Sheehy, Hillary Clinton's biography

He may be facing up to life out of political office, but Mrs Clinton's new job ensures that the Clinton political legacy will continue to grow.

Having redefined the role of first lady, she is now charting a path that brings her out of the shadow of her husband.

"She is his living legacy," says Gail Sheehy, author of "Hillary's Choice", a biography of Hillary Clinton.

Moving out of the shadows

But she is also the one person who has helped shape his legacy more than any other.

When Bill Clinton came to office, he did so under the slogan "two for the price of one".

Hillary Clinton never intended to be the traditional first lady.

A highly ambitious and successful lawyer who had made significant career sacrifices and compromises to help her husband win the presidency, she wanted a substantive role in his White House.

At heart of power

She immediately broke new ground by moving the first lady's office to the heart of power in the White House West Wing.

And within weeks, President Clinton announced that she would be heading a project to reform the nation's healthcare system.

"She never was the first lady," says Ms Sheehy, "She was always the co-president, even though that suited her more than it did the American people."

Mrs Clinton's healthcare reform scheme proved to be a disaster which died on the floor of Congress, and the series of scandals that dogged the Clinton era in the years that followed forced her to take more of a back seat, publicly at least.

Breaking the mould

But though their relationship went through some of its darkest hours during the Lewinsky scandal, she continued to have her husband's ear.

The president will have to be content with a supporting role

"In virtually every way, from her forays into health policy, to her role behind the scenes, to the way she came out of the Lewinsky scandal and tried to establish her own identity, she really broke the mould," says Michael Tomasky, author of "Hillary's Turn".

It was the moment when she won the New York senate race that Hillary Clinton ensured that she had continued to redefine her role.

Future president?

"Hillary Clinton is writing an entirely new story," says Gail Sheehy.

"She is probably the most powerful woman on the political scene, and she is walking into the senate as the woman who will keep the lights on for the Democrats in exile."

And that inevitably raises the question, will she now run for president? Whether it's in 2004 or 2008, many people believe she will.

"It was her secret slogan," says Ms Sheehy. "Eight years of Bill, eight years of Hill. This is not a new idea."

And it is an idea said to be wholeheartedly endorsed by her husband.

Bill's new role

Which may answer the question many are asking about what he intends to do now.

He is on the point of choosing an office in Manhattan, and is weighing up several possibilities, including writing his book, and setting up some kind of an international foundation.

But perhaps the man who loves campaigning more than anything else is just hanging on until he can throw himself into yet another campaign, for another Clinton to become president of the United States.

One thing is certain, the Clinton presidency may be over for now, but the Clinton legacy continues to be shaped.