With the Democratic Party officially nominating Sen. Barack Obama as their presidential candidate and Republican Sen. John McCain picking a woman as his running mate, the race for the White House ended the week on an historic note. When Obama took the stage on the last night of his party's convention to address an audience of more than 80,000 people in Denver's Invesco Field, many of whom had waited hours to hear him speak -- and the 38 million who watched him on television -- the challenges he faced were clear: The candidate had to link his policies to the needs of struggling American voters and take direct aim at his opponent Sen. John McCain and the attacks levied on him that he simply is not experienced or tough enough to be the nation's next commander in chief. Obama did just that and more, tying McCain directly to the policies of President George W. Bush, which he declared have threatened the American promise during the past eight years. "Now let there be no doubt. The Republican nominee, John McCain, has worn the uniform of our country with bravery and distinction, and for that we owe him our gratitude and respect. And next week, we'll also hear about those occasions when he's broken with his party as evidence that he can deliver the change that we need," said Obama. Larry Berman, a professor of political science at UC Davis, thinks Obama hit all of the right marks. "He'd set high expectations, but exceeded them. It was an extraordinary speech with respect to what he wanted to do to launch his campaign for the general election. He gave people a vision about how good America could be and appealed to the essence of what America meant to him," says Berman. Obama's speech marked the end of a generally successful convention that aimed to unify the party and reintroduce the candidate and his family to American voters who are still undecided. "I was struck by the progressive character of the convention itself. The first night did begin slowly, but it was a necessary first step to introduce Michelle Obama to the American public. It was really important to begin like that and to answer this issue of whether this was going to be [Sen. Hillary and former President Bill] Clintons' convention. Both Clintons have now diffused the issue that this was going to be a divided convention about where would Hillary's supporters go," says Berman. The night was also steeped in historic symbolism and sentiment, marking the 45th anniversary of Dr. Martin Luther King, Jr.'s "I Have a Dream" speech. Obama did not evoke King until the end of his speech, which disappointed San Francisco State University political scientist Robert Smith. "Obama summed up all the themes of the convention very well, but didn't reach the level of previous speeches; it was more workmanlike. Obama underplayed his strengths, which are inspiration, hope, change, not policy, policy, policy." Obama's strategy appears to have worked, however. The latest Gallup daily tracking poll shows Obama with an eight-point lead. In the days leading up to the Democrats' convention, the two candidates were tied in the polls. But in a strategic move to take the attention off Obama and on to his own campaign, McCain celebrated his 72nd birthday by naming relatively unknown Alaska Gov. Sarah Palin, who is only 44, as his second, and ending speculation that the second spot would go to former rival Mitt Romney or Minnesota Gov. Tim Pawlenty.