Barack Obama says the nation has had enough of "broken politics" and "the failed policies of George W. Bush."

Obama was greeted by more than 80,000 cheering supporters at Denver's Invesco Field at Mile High. His acceptance of his party's nomination makes him the first black American to hold a such a position from a major party.

Obama promised to cut taxes for nearly all working-class families, end the war in Iraq and break America's dependence on Mideast oil within a decade.

He also attempted to link his criticism of President Bush to John McCain. He said McCain is worthy of respect for his service to the nation, but that when it comes to the problems of working people, McCain "just doesn't get it."

He said electing McCain would mean four more years of the last eight and that he welcomes a debate on the issues.