Michele Bachmann - right candidate for Mrs President?

In a spirited speech to the Republican Leadership Conference in New Orleans this weekend Bachmann, 55, - who announced her presidential intentions last Monday - called for schools to teach the doctrine of intelligent design, and exposed her own doubts about Darwin's theory of evolution.

She said: "What I support is putting all science on the table and letting students decide.

"I don't think it's a good idea for government to come down on one side of a scientific issue or another, when there is reasonable doubt on both sides … That's why I believe the federal government should not be involved in local education to the most minimal process."

Bachmann, Congresswoman for Minnesota, is riding a wave of support after her triumphant showing at the first Republican debate in New Hampshire last Monday night.

In New Orleans this weekend she was greeted with a standing ovation and an audience member shouting "I love you!" as she walked on stage.

"Love you too," she replied, according to the CBS news channel.

She roused the New Orleans crowd by telling them: "You survived Katrina! You survived President (Barack] Obama's oil moratorium! There is nothing you cannot survive!"

And she declared that in 2012 the Tea Party - a right-wing grassroots movement which is now in the driving seat within the Republican party - "will be bigger than ever".

Throughout the week she has caused most excitement among Republicans, not least for her ability to energise supporters. "She gets people fired up," said Andrew Hemingway, chair of the Republican Liberty Caucus of New Hampshire.

And while the battle for the Republican nominee has only just begun, the sometimes fractious Republican loyalists appeared to be agreed on at least one thing about the 2012 White House race this weekend - Obama has got to go.

Many of the officials and activists attending the three-day conference, which ends today, said the party should move beyond recent ideological battles and unite behind a 2012 nominee who can beat Obama.

"Our goal, our focus, has to be to elect a new Republican president next year," said Mississippi governor Haley Barbour, who considered a White House run but decided against it.

"Don't get hung up on purity. In this business, it is unity that wins elections," he said.

Republicans are launching their 2012 race to find a challenger to Obama with fresh memories of last year's divisive primary fights between the party establishment and even more conservative Tea Party insurgents, which might have cost the party gains in the midterm elections.

In 2012, many of the activists said, the focus will be less on ideology and more on practicality. "It's not about finding somebody who we agree with, but who the American people agree with," said Linda Herren, a member of the Republican National Committee from Georgia. "I can tell you I won't agree 100 per cent with our candidate, but I will support whoever wins the primary. We have to beat Obama."

The slow-starting Republican presidential race has gained momentum in recent weeks, although most national polls show all of the Republicans trailing Obama 17 months before the election.

Four Republican presidential hopefuls, including Bachmann, addressed the crowd of nearly 2,000 on Friday, and made their case for why they were the best person to challenge the Democrat president.

All of the contenders slammed Obama's economic leadership and criticised his policies as a dramatic expansion of government control and regulation that had stifled growth and drained the budget.

"There is a sense of urgency for us to take this nation back," said businessman Herman Cain, who drew a big crowd and a rousing reception. He mocked critics who say he has no political experience and doesn't know how things work.

"I'm going to Washington to change how things work," he said.

US Representative Ron Paul and former US Senator Rick Santorum also addressed the conference, which has about 2,000 registrants - fewer than last year, when 2008 vice-presidential nominee Sarah Palin was a featured speaker.

Former Alaska governor Palin, still considering a White House bid, did not attend the event, and neither did two top-tier contenders, Mitt Romney and Tim Pawlenty. Former US envoy Jon Huntsman, who will launch his candidacy next week, was scheduled to attend but cancelled because of illness.

Barbara Mabray, of Galveston, Texas, said she came to support an effort to draft US Senator Jim DeMint, a conservative who led the challenge to party establishment candidates in several of last year's primaries. "We need someone of his stature, a proven person," she said. "I want someone who can win."

Texas Governor Rick Perry, another possible contender, is still considering joining in the race in response to complaints about the weakness of the field.