U.S. Senator Hillary Clinton on Saturday took the first step toward running for president in 2008, with the words "I'm in" posted on her website.

"And I'm in to win," Hillary said in a video massage on the website, announcing that she has set up an exploratory committee that can gauge opinions and raise money for a presidential campaign.

Bringing "the right end" to the war in Iraq, reducing the deficit, making the country energy independent and affordable health care are among issues Hillary touted in her announcement.

"After six years of George W. Bush, it is time to renew the promise of America," she said.

"I grew up in a middle-class family in the middle of America, and we believed in that promise," the 59-year-old said.

"I still do. I've spent my entire life trying to make good on it," said Hillary. 

Democratic front-runner

Over the years, the former first lady has become a major political figure in her own right - She is broadly popular with women, African-Americans, and other core groups in the Democratic Party, and she has become one of the party's best fundraisers and most sought-after speakers.

While she is not associated with any major piece of legislation, she is widely regarded as an effective, thoughtful lawmaker who has built bipartisan ties.

Hillary is the seventh Democrat to join the likely field of candidates that will officially start vying for the Democratic nomination next January, in the Iowa presidential caucuses.

At present, she appears at the head of the Democratic pack in many national polls, yet she is in a tighter spot in some voter surveys in Iowa and New Hampshire, which kick off the presidential nominating process.

Recent polls showed Senator Barack Obama of Illinois and former Senator John Edwards of North Carolina, the other two top Democratic presidential contenders, doing well in those states.

Should Hillary win, she would be the first woman to serve as president of the United States - and the first presidential spouse to do so as well. Her husband Bill Clinton served two terms from 1993-2001. 

More barriers to overcome

From now on, Hillary has embarked on a journey in which she needs to overcome more political barriers in her extraordinary and controversial career.

In her video message, she squarely confronted an issue that concerns many Democrats: Whether she can, in fact, win the presidency.

The facts confronting her are that some voters still associate her most with the controversies of the Clinton administration, and Republicans have long attacked and caricatured her, and plan to brand her as indecisive on Iraq.

"I have never been afraid to stand up for what I believe in or to face down the Republican machine," Hillary said.

"After nearly 70 million U.S. dollars spent against my campaigns in New York and two landslide wins, I can say I know how Washington Republicans think, how they operate, and how to beat them," she added.

Her husband left office in 2000 after two terms marked by robust economic expansion and a series of investigation into his personal life and the couple's business dealings.

The successes and shadows of those years will likely loom over Hillary, who was both a hands-on adviser and a divisive presence in her husband's administration.

Moreover, Hillary's early support for the Iraq war, and her unpopularity in the 1990s have stirred doubts among Democrats about whether she can win the presidency.

Her supporters acknowledged that part of her challenge is letting voters see the full her and not simply a controlled, rehearsed politician -- no easy task for such a private and protective person.

Hillary has said she is a far better lawmaker and politician today because of her experiences and lessons during the White House years.

Yet analysts said it is unclear how difficult it will be to persuade Americans to see her in a fresh light and give her a full hearing, given that she is so well known and that voters' attitudes about her are so firmly shaped at this point.

Editor: Yan