Standing in the centre of an arena here, surrounded by thousands of Republican delegates, McCain firmly signaled that he intended to seize the mantle of change Obama claimed in his own unlikely bid for his party’s nomination.

McCain suggested that his choice of Gov. Sarah Palin of Alaska as his running mate gave him the license to run as an outsider against Washington, even though he has served in Congress for more than 25 years. “Let me just offer an advance warning to the old, big-spending, do-nothing, me-first-country-second crowd: Change is coming,” McCain said.

With his speech, McCain laid out the broad outlines of his general election campaign. He sought to move from a convention marked by an intense effort to reassure the party base to an appeal to a broader general election audience that polling suggests has turned sharply on Republicans and President Bush. He invoked, in one of the most emotional moments of the night, his struggles as a prisoner of war in Vietnam.

McCain also returned to what has been his signature theme as a candidate, including in his unsuccessful 2000 campaign: that he is a politician prepared to defy his own party. He used the word “fight” 43 times, as he sought to present himself as the insurgent he was known as before the primaries, when he veered to the right.

“Stand up, stand up, stand up and fight,” he said at the end of his speech. “Nothing is inevitable here. We're Americans, and we never give up. We never quit. We never hide from history. We make history.”

Much of the address, though delivered at one of the most prominent moments of a presidential campaign, was little different from the stump speech he has been delivering across the country. And it was often offered in a monotone as he stood before a solid-colour backdrop that flicked from green to blue. The reaction was far more subdued than it was the night before for his running mate, Palin. There were stretches in which he drew only a smattering of applause.

“I liked the conservative tone and that he was talking about being prolife, self-sufficient — let's keep the money from countries that don’t like us,” said Peggy Lambert, a delegate from Maryville, Tennessee. “But man, Sarah Palin! John is gonna have trouble keeping up with her.”

One of the livelier moments of the evening came when McCain was interrupted by several antiwar protestors who had infiltrated the hall. Their signs were quickly ripped from their hands, and they were carried out as the crowd shouted, “USA! USA!”

McCain, who by now has become accustomed to these kinds of interruptions, responded with a smile. “Please don't be diverted by the ground noise, the static,” McCain said, before adding “Americans want us to stop yelling at each other.”

McCain faced the challenge on Thursday of pivoting from making an appeal to Republican base voters to reaching out to the larger general election audience watching him. Accordingly, there were relatively few mentions of divisive social issues as he returned to the way he has historically presented himself: as an iconoclast willing to challenge his own party. That image was shaken this year as he as appeared to adjust some positions in navigating the primaries.

“You know, I’ve been called a maverick, someone who marches to the beat of his own drum,” he said. “ 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 paid only the most fleeting tribute to Bush, not even using his name. “I’m grateful to the president for leading us in those dark days following the worst attack on American soil in our history, and keeping us safe from another attack many thought was inevitable,” he said at the opening of his speech.

McCain defined bipartisanship as not only working with the opposite party but being prepared to work against his own, even though he is aligned with Bush on two of the biggest issues facing the country: the Iraq war and the economy.

That pledge of political independence and bipartisanship could prove especially valuable at a time when the Republican Party is so unpopular.