Of the leading contenders, George W Bush, the Governor of Texas, avoided the twin pitfalls of gaffe and ignorance; Senator John McCain displayed his breadth of experience and quickness of wit; Steve Forbes, the millionaire publisher, capitalised on his sober-suited managerial competence; and Gary Bauer, the Christian conservative, was articulate and unswayed in defence of his principles.
Yet there was a clear winner in this carefully constructed question and answer session: Mr McCain, who impressed, charmed and amused by turns, rapidly shedding his uncharacteristic diffidence.
Mr Bush, in his first national television debate, seemed unsure whether to stand aloof as the front-runner or muck in as one of the boys, and he shifted uneasily between the two approaches, his discomfort palpable.
For both Mr McCain and Mr Bush, much was at stake. After a month-long surge in opinion polls during which he pulled ahead of Mr Bush in New Hampshire, Mr McCain was again losing ground. Mr Bush had planned not to take part in debates before the new year, but was forced by Mr McCain's rise in this key state to change his mind. The New Hampshire primary election, which will help to determine who wins the Republican nomination, is now less than two months away.
The candidates had rolled into the city of Manchester like minor heads of state in their limousines, slowing for the approach to the local broadcasting station to acknowledge the cheers of their supporters.
Just across the road, several hundred McCain supporters crammed into Jillian's, Manchester's premier sports bar, which had switched its giant screens from football to politics for the evening.
When the genial face of George Bush appeared on screen in his latest campaign advertisement - "Every child... should share in the American dream" - there were loud boos.
As Mr McCain was introduced, the second of the six candidates, the cheers rang out. There were tables of military veterans in their studded caps - a constituency for which Mr McCain as a Vietnam war hero has a special appeal - but ranks of young people, too, including a spectacular punk with a red Mohican hair-do, for whom Mr McCain's anti-establishment image is the chief draw.
Chatting amiably through the fiery rhetoric of the black conservative, Alan Keyes, and the languid explanations of the sixth candidate, Senator Orrin Hatch, the McCain fans called for a respectful silence whenever a question was directed at their candidate, and then dissolved into laughter when, in response to a question about his well known temper, he quipped: "A comment like that really makes me mad." Or, when asked about economic policy, he said that not only would he keep on the present chairman of the Federal Reserve, Alan Greenspan, but that, if he died, he would want him propped up in a corner thereafter.
With his huge poll lead nationally, Mr Bush has no immediate cause for worry, but the race is not over. The candidates are back in the debating studio on Monday - in Mr McCain's home state of Arizona this time - for another round.