Democratic Sen. Hillary Rodham Clinton embarked on a widely anticipated campaign for the White House on Saturday, a former first lady intent on becoming the first female American president. "I'm in and I'm in to win," she said on her Web site. Clinton's announcement, days after Sen. Barack Obama shook up the contest race with his bid to become the first black president, establishes the most diverse political field ever. Clinton is considered the front-runner, with Obama and 2004 vice presidential nominee John Edwards top contenders. New Mexico Gov. Bill Richardson, who would be the first Hispanic president, intends to announce his plans on Sunday. In a videotaped message, Clinton invites voters to begin a dialogue with her on the major issues - health care, Social Security and Medicare, and the war in Iraq. "I'm not just starting a campaign, though, I'm beginning a conversation with you, with America," she said. "Let's talk. Let's chat. The conversation in Washington has been just a little one-sided lately, don't you think?" Clinton, who was re-elected to a second term last November, said she will spend the next two years "doing everything in my power to limit the damage George W. Bush can do. But only a new president will be able to undo Bush's mistakes and restore our hope and optimism." In a defiant statement - and a nod to questions about her electability - Clinton said: "I have never been afraid to stand up for what I believe in or to face down the Republican machine. After nearly $70 million 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 said she planned to host live online video chats with voters beginning Monday.