"Eight is enough," Barack Obama said as he accepted the Democratic Party nomination Thursday night and vowed to fix the failed policies of incumbent U.S. President George W. Bush.

"We love this country too much to let the next four years look just like the last eight," he told an estimated 75,000 people packed into a Denver football stadium. "On November 4th, we must stand up and say -- eight is enough."

"We are better than these last eight years," Obama said to deafening applause and cheers. "We are a better country than this."

Throughout his one-hour conversation with millions of voters in primetime, Obama linked his opponent, Republican Sen. John McCain, to the policies of the Bush administration. "John McCain has voted with President Bush 90 percent of the time," a scathing indictment of his Republican rival -- on health care, education, the economy and more.

"We meet at one of those defining moments -- a moment when our nation is at war, our economy is in turmoil, and the American promise has been threatened once more," Obama 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 policies of George W. Bush."

"Senator McCain likes to talk about judgment, but really, what does it say about your judgment when you think George Bush has been right more than ninety percent of the time?" Obama said. "I don't know about you, but I'm not ready to take a 10 per cent chance on change."

Obama also hoped to dispel concerns he won't be as tough as Republicans would be on national security issues.

"When John McCain said we could just 'muddle through' in Afghanistan, I argued for more resources and more troops to finish the fight against the terrorists that actually attacked us on 9/11," he said. "You know John McCain likes to say he will follow Osama Bin Laden to the gates of hell, but he won't even follow him to the cave where he lives.

"We are the party of Roosevelt. We are the party of Kennedy. So don't tell me that Democrats won't defend this country. Don't tell me that Democrats won't keep us safe.

"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.

Obama used his big moment to repeat the campaign promises that would define his presidency, focusing on the economy:

• A tax cut for 95 per cent of all working families
• A tax code that "doesn't reward the lobbyists who wrote it, but the American workers and small businesses who deserve it."
• Stopping tax breaks to corporations outsourcing jobs overseas, and giving them to companies that create them in the U.S.
• The elimination of capital gains taxes for small businesses and start-ups creating high-wage, high-tech jobs
• The end of American dependence on oil from the Middle East within 10 years

Former Vice-President Al Gore, who spoke shortly before Obama, reminded his audience that he knew all to well the strains of a tight presidential race -- referring to his own loss to Bush eight years ago.

"Today, we face essentially the same choice we faced in 2000," Gore said. "John McCain, a man who has earned our respect on many levels, is now openly endorsing the policies of the Bush-Cheney White House and promising to actually continue them, the same policies all over again."

"If you like the Bush-Cheney approach, John McCain's your man," Gore said. "If you want change, then vote for Barack Obama and Joe Biden."

Gore said the 2008 election is so close because the defenders of the status quo are "desperately afraid of the change Barack Obama represents."

With the dependence on foreign oil being both an economic and environmental hurdle, Gore said all the tools are in place to start the switch to renewable energies -- that is, besides a president in the White House to support such initiatives.

"And we know how to fix that, don't we?" Gore asked the crowd, who roared back an enthusiastic response.

Stars come out in Denver

The final night of the Democratic National Convention was an event in its own right. Jennifer Hudson, the Academy Award-winning performer, was on hand to sing the national anthem; Michael McFonald sang "America the Beautiful" and there were musical performances by Stevie Wonder, Sheryl Crow, and others in the hours before Obama's address.

Crow's set included a slightly modified version of her hit "A Change Will Do You Good." She instead sang "Change Will Do Us Good."

Other speakers included New Mexico Governor Bill Richardson, the grand-daughter of former Republican President Dwight Eisenhower and, in an unscheduled appearance, Obama's running mate Joe Biden.

Meanwhile, McCain was in Ohio as Obama accepted the Democratic nomination. McCain's campaign aired a one-night-only advertisement, congratulating Obama and noting the acceptance speech came on the 45th anniversary of Dr. Martin Luther King's famous "I Have a Dream" speech on the steps of the Lincoln Memorial in Washington.

"Senator Obama, this is truly a good day for America. Too often the achievements of our opponents go unnoticed. So I wanted to stop and say, 'Congratulations,"' McCain said.

"How perfect that your nomination would come on this historic day. Tomorrow, we'll be back at it. But tonight Senator, job well done."

McCain is widely believed to have chosen his running mate, and an announcement of the pick could come Friday. The Republican party meets next week to make the nomination official.

The first debate between the two candidates is scheduled for Sept. 26 at the University of Mississippi.