John McCain accepted the Republican presidential nomination Thursday night vowing to vanquish the "constant partisan rancor" that grips Washington and promised "change is coming" during his speech at the Republican National Convention in St. Paul, Minnesota.

To repeated cheers from his delegates, McCain criticized fellow Republicans as well as Democratic rival Barack Obama as he reached out to independents and disaffected Democrats.

"We were elected to change Washington and we let Washington change us," he said of the Republicans who controlled Congress for most of the past 15 years.

As for Obama, he said, "I will keep taxes low and cut them where I can. My opponent will raise them. I will cut government spending. He will increase it."

McCain's wife, Cindy, and running mate Sarah Palin and her husband joined him on stage as tens of thousands red, white and blue balloons cascaded from high above the convention floor.

"She stands up for what's right and she doesn't let anyone tell her to sit down," McCain had said of the woman who has faced intense scrutiny in the week since she was picked. "And let me offer an advance warning to the old, big-spending, do-nothing, me-first, country-second Washington crowd: Change is coming," McCain declared.

He and Palin were departing their convention city immediately after the Arizona senator's acceptance speech, bound for Wisconsin and an early start on the final weeks of the White House campaign.

McCain, at 72, bidding to become the oldest first-term president, drew a roar from the convention crowd when he walked out onto the stage lighted by a single spotlight. He was introduced by a video that dwelt heavily on his time spent as a prisoner of war in Vietnam and as a member of Congress, hailed for a "faithful unyielding love for America, country first." "USA, USA, USA," chanted the crowd.

McCain faced a delicate assignment as he formally accepted his party's presidential nomination, presenting his credentials as a reformer willing to take on his own party and stressing his independence from an unpopular President Bush all without breaking faith with his Republican base.

He set about it methodically. "After we've won, we're going to reach out our hand to any willing patriot, make this government start working for you again," he said, and he pledged to invite Democrats and independents to serve in his administration.

He mentioned President Bush only in passing, as the leader who led the country through the days after the terror attacks on September 11, 2001.

And there was plenty for conservative Republicans to cheer, from his pledge to free the country from the grip of its dependence on foreign oil to a vow to have schools answer to parents and students rather than "unions and entrenched bureaucrats."

A man who has clashed repeatedly with Republicans in Congress, he said proudly, "I've been called a maverick. Sometimes it's meant as a compliment and sometimes it's not. What it really means is I understand who I work for. "I don't work for a party. I don't work for a special interest. I don't work for myself. I work for you."

McCain invoked the five years he spent in a North Vietnamese prison. "I fell in love with my country when I was a prisoner in someone else's. I was never the same again. I wasn't my own man anymore. I was my country's."

The polls indicate a close race between McCain and Obama, at 47 a generation younger than his Republican opponent, with the outcome likely to be decided in scattered swing states in the industrial Midwest and the Southwest.

McCain won the presidential nomination late Wednesday night in an anticlimactic vote that followed a campaign lasting most of a decade. He first ran for the White House in 2000, but lost the Republican nomination to Bush in a bruising struggle.