DENVER — Barack Obama reached for Martin Luther King Jr.'s dream Thursday night as he embarked on the final lap of his history-making bid to become the nation's first black president. And Obama, surrounded by an enormous and adoring crowd, said it is time for America to live up to the ideals and hopes of the slain civil rights leader.

"Tonight, more Americans are out of work and more are working harder for less," said Obama in a nomination acceptance speech before an estimated 84,000 people in Invesco Field at Mile High Stadium.

"More of you have lost your homes and more are watching your home values plummet. More of you have cars you can't afford to drive, credit card bills you can't afford to pay and tuition that is beyond your reach," he said. "These challenges are not all of government's making. But the failure to respond is a direct result of a broken politics in Washington and the failed presidency of George W. Bush. I say enough."

Obama delivered his nomination-acceptance speech on the 45th anniversary of the day King stood on the steps of the Lincoln Memorial in Washington, D.C., to deliver his now-famous speech that has since been titled "I Have a Dream."

King said: "I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character."

Obama, calling his speech "The American Promise," hopes that dream will carry over into November's ballot box.

Introduced by a moving video about his parents and grandparents, and chants from the crowd of "Yes, we can!" he summed up his story in his speech: "A brief union between a young man from Kenya and a young woman from Kansas who weren't well-off or well-known, but shared a belief that in America, their son could achieve whatever he put his mind to."

And while many may believe it came too late, history was made when Obama became the first black man to accept the nomination of a major party to run for president of the United States of America.

Supporters at the Broncos' stadium were not disappointed. Obama, known for his speech-making, heard yells as loud as any heard by legendary quarterback John Elway — ovations that occasionally drowned out what the Democratic nominee was saying.

Obama hit on a number of issues where Republicans say he is weak.

"As commander-in-chief, I will never hesitate to defend this nation, but I will only send our troops into harm's way with a clear mission and a sacred commitment to give them the equipment they need in battle and the care and benefits they deserve when they come home," he said. "I will end this war in Iraq responsibly and finish the fight against al-Qaida and the Taliban in Afghanistan.'

And Obama verbally jabbed at John McCain, the GOP candidate who is expected to win his party's nomination next week at the Republican National Convention in St. Paul, Minn.

"John McCain likes to say that he'll follow bin Laden to the Gates of Hell — but he won't even go to the cave where he lives."

He also attacked the campaign methods employed by Republicans.

"If you don't have any fresh ideas, then you use stale tactics to scare the voters," he said. "If you don't have a record to run on, then you paint your opponent as someone people should run from."

And he also addressed those who may not vote for him because of his skin color or his name.

"You make a big election about small things," he said.

While he also delivered a lot of attacks on McCain, he also had a lot of optimism in his words. He also continually returned to the campaign theme of change.

"But I stand before you tonight because all across America something is stirring," he said. "The change we need doesn't come from Washington. Change comes to Washington."

His speech tackled many significant issues, including the economy.

"The fundamentals we use to measure economic strength are whether we are living up to that fundamental promise that has made this country great — a promise that is the only reason I am standing here tonight," he said.

Obama said he will stop giving tax breaks to corporations that ship jobs overseas and start giving them to companies that create good American jobs.

"I will cut taxes for 95 percent of all working families. Because in an economy like this, the last thing we should do is raise taxes on the middle class," Obama said.

Speaking of his wife, Obama said: "Michelle and I are only here tonight because we were given a chance at an education. And I will not settle for an America where some kids don't have that chance."

Speaking about what America can do, he said: "It is the American spirit — that American promise — that pushes us forward even when the path is uncertain; that binds us together in spite of our differences; that makes us fix our eye not on what is seen, but what is unseen, that better place around the bend."

Obama said it was the promise of a better America that 45 years ago drew people from faraway places to hear a young preacher from Georgia speak of his dream.

"America, we cannot turn back. We cannot walk alone," he said near the end of his speech. "At this moment, in this election, we must pledge once more to march into the future. Let us keep that promise — that American promise — and in the words of scripture, hold firmly, without wavering, to the hope that we confess."

While Obama was the headliner, he was not the only notable speaker.

Former Vice President Al Gore, who narrowly lost to Bush eight years ago, told the crowd, "So why is this election so close? Well, I know something about close elections, so let me offer you my opinion. I believe this election is close today mainly because the forces of the status quo are desperately afraid of the change Barack Obama represents," he said.

"You recognize that he represents a clean break from the politics of partisanship and bitter division. You understand that the politics of the past are exhausted, and you're tired of appeals based on fear. You know that America is capable of better than what you have seen in recent years. You are hungry for a new politics," Gore said.

Finally, it was a party at Mile High, with Sheryl Crow,, and Stevie Wonder performing. Many in the crowd were dancing and singing along when Wonder sang "Signed, Sealed, Delivered, I'm Yours."

Comments by other speakers at Thursday night's historic event:

• Martin Luther King III: "While waiting to come to the podium, I could not help thinking how proud my father would be: proud of Barack Obama, proud of the party that nominated him and proud of the America that will elect him."

• The Rev. Bernice King, daughter of King Jr.: "Tonight, freedom rings! From the snow-capped Rockies of Colorado, freedom rings!"

• Rep. John Lewis, D-Ga.: "I was there that day when Dr. King delivered his historic speech before an audience of more than 250,000. I am the last remaining speaker from the March on Washington, and I was there when Dr. King urged this nation to lay down the burden of discrimination and segregation and move toward the creation of a more perfect union."

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