Senator Barack Obama officially launched his bid for the US Presidency on Saturday in Springfield, Illinois outside the Old State Capitol building where President Abraham Lincoln delivered his historic “house divided” anti-slavery speech in 1858.

“I recognize there is a certain presumptuousness - a certain audacity - to this announcement,” he said. “I know I haven't spent a lot of time learning the ways of Washington. But I’ve been there long enough to know that the ways of Washington must change.”

In his speech, Sen. Obama vowed to transform US politics and wrest the controls of government from “… the cynics, and the lobbyists, and the special interests who’ve turned our government into a game only they can afford to play.”

Playing his freshman senator status to his advantage, untainted by ‘the ways of Washington’, Sen. Obama also spoke of his distaste for bitterly divisive partisan politics, which will almost certainly resonate favorably with US voters.

As supporters and curious onlookers crowded the stage, Sen. Obama blamed poor leadership and political gridlock for national crises related to energy, climate change, education, health care, the plight of the working poor and the Iraq war, which he collectively called the “challenges of this millennium”.

“All of us know what those challenges are today,” he said. “What’s stopped us from meeting these challenges is not the absence of sound policies and sensible plans. What’s stopped us is the failure of leadership, the smallness of our politics – the ease with which we’re distracted by the petty and trivial.”

Senator Obama has one significant advantage that distinguishes him from his higher profile Democratic challengers, Sen. Hillary Clinton (N.Y.) and former Sen. John Edwards (N.C.) – he has long opposed the war in Iraq and will not need to repeatedly explain why he supported the invasion but opposes the war now.

When the US Congress passed the 2002 Iraq Resolution, Sen. Obama was an Illinois State Senator who publicly opposed the invasion, which he called “dumb”, and warned that the US faced a long and potentially disastrous occupation in Iraq. He now supports a phased withdrawal of US troops and opposes President Bush’s plan to send 21,500 more troops to Iraq.

“America, it’s time to start bringing our troops home,” Sen. Obama told the crowd on Saturday. “Letting the Iraqis know that we will not be there forever is our last, best hope to pressure the Sunni and Shia to come to the table and find peace.”

The Iraq war will be a critical issue in the lead up to the primaries and the presidential election, given that it was a determining factor at the mid-term elections, when US voters rejected the war and put Democrats in charge of both Houses of Congress.

Senator Obama’s rise from State Senator to US Presidential hopeful has been swift. Even before being elected to the US Senate, he electrified the 2004 Democratic convention with a hard-hitting, much-lauded keynote address in which he coined the phrase “the audacity of hope”.

The son of a white mother from Kansas and a black father from Kenya, Sen. Obama has written two best-selling books, including an autobiography entitled Dreams from My Father: A Story of Race and Inheritance and his more recent political tome, The Audacity of Hope: Thoughts on Reclaiming the American Dream, published in October 2006.

Senator Obama has a BA from Columbia University where studied political science and international relations. In 1991, he obtained his JD degree magna cum laude from Harvard, where he became the first African-American president of the Harvard Law Review. He has since worked as a civil rights lawyer, taught constitutional law and served for eight years in the Illinois State Legislature until his election to the US Senate in 2004.