The Democrats presidential candidate for the next election

happen?

Hillary Clinton's announcement sets up the intriguing prospect of a race between a female and a black candidate for the White House. By David Usborne

Hillary Rodham Clinton, the US Senator from New York and former First Lady, yesterday answered months of fevered speculation about her White House ambitions and formally embarked on what will be a historic campaign to become the first woman president of the United States.

The Senator, who only won re-election to a second six-year term as a US Senator last November, shot out of the starting gate with a feisty video-taped statement on her website, making clear her determination to sweep aside any competition in 2008. "I'm in, and I'm in to win," she declared.

Her announcement comes just days after her Democrat colleague in the Senate, political superstar Barack Obama of Illinois, similarly made a widely anticipated first step towards joining the fast-growing field of presidential contenders hoping to become the country's first black commander-in-chief.

The timing is no accident, with Mrs Clinton clearly anxious to seize some of the political wind from Mr Obama's sails and slow his momentum. The sudden surfacing of Senator Obama as a serious candidate - he began hinting at it only late last year - has seriously scrambled calculations in the Clinton camp.

Even though almost two years of George Bush's tenure remain, the 2008 campaign to replace him has already begun. It promises not only to be one of the most thrilling and unpredictable in a generation, it will surely be the most expensive race ever seen.