Audience members react as U.S. Rep. Michele Bachmann, R-Minn., speaks during the Conservative Principles Conference hosted by U.S. Rep. Steve King, R-Iowa, Saturday in Des Moines. (Charlie Neibergall/AP)

In these preliminary stages of the contest for the 2012 Republican presidential nomination, Iowa conservatives have begun to flex their muscles and the candidates are responding.

Five potential candidates — party veterans and long shots alike — came here Saturday for a day of attacks on President Obama’s policies, talk of constitutional principles and a chance to gauge the mood of the most conservative wing of the GOP base.

Rep. Steve King (R-Iowa), one of the most conservative members of the House, hosted the day-long conference, which drew hundreds of activists. It was the second conservative gathering of the month in the state to draw a handful of presidential hopefuls — the first was hosted by a religious conservative group — and was another reminder of how deeply intertwined fiscal and cultural issues are in the state with the nation’s first presidential caucuses.

The possible presidential candidates included Mississippi Gov. Haley Barbour, former House speaker Newt Gingrich, businessman Herman Cain, and former United Nations ambassador John Bolton. But it was Rep. Michele Bachmann (R-Minn.) who lit up the gathering with a rapid-fire denunciation of the president that had the audience on its feet cheering.

“Are you in for 2012?” she called out to the audience. “Are you in? Are you going to make it happen? Are we going to take our country back?” As the applause built, she concluded by saying, “I agree with you. I say we do. I say I’m in. You’re in. We will take this back in 2012.”

Barbour and Gingrich, who are moving rapidly toward active candidacies for the 2012 Republican nomination, took sharp aim at the president and his policies. Barbour said the president’s policies were hurting the economy. Gingrich accused Obama of being a “spectator” rather than a commander-in-chief on foreign policy.

Bolton delivered a withering critique of Obama’s foreign policies and said the incumbent is not qualified to handle those issues, even after two years in office. Cain, another crowd pleaser, railed against liberals and, holding nothing back, asserted, “Stupid people are ruining this country.”

Saturday’s audience did not constitute a full cross section of the likely participants in Iowa’s first-in-the nation caucuses. But as a measure of core conservative sentiment — and influence — it offered an early indication of the kind of message these activists are hungering to hear. Barbour and Gingrich, two of the most veteran politicians in the GOP, drew warm welcomes, but not the kind of reception afforded Bachmann.

“If she decides to enter the race, she will be a significant player,” said King, a close ally of Bachmann’s in the House. “The response to her was the strongest response to anyone . . . the room was electric. And that’s not spin.”

Sen. Jim DeMint (R-S.C.), a favorite of tea party activists for his challenges to party leadership and establishment-backed candidates during the 2010 primaries, was scheduled to deliver the keynote address at a dinner Saturday night. Earlier in the day he expressed his belief that the current field of likely candidates could see new entrants within a few months unless someone begins to catch fire.

“If no one is an immediate frontrunner, I think you might see a whole new cast of Republican candidates within the next couple months,” said DeMint, who reiterated that he will not run. He declined to name anyone but said there were potentially good candidates among the nation’s Republican governors.

Bachmann’s possible candidacy could affect the campaigns of others already at work here. They include former Minnesota governor Tim Pawlenty, and former Pennsylvania senator Rick Santorum, who is courting social and religious conservatives. But she could also affect decisions by former Arkansas governor Mike Huckabee, who won the caucuses in 2008, and former Alaska governor Sarah Palin, neither of whom has taken the kind of steps others have to prepare for a race.

Barbour said the key to victory in 2012 will be to outline policies that are in dramatic opposition to Obama’s. “The Obama administration is populated by people who have of unlimited faith in limitless government,” he said. “They think a bigger government means a bigger economy. Well, let me tell you flatly, a bigger government means a smaller economy.”

Gingrich spent part of his speech defending himself against charges that he has changed positions on U.S. policy in Libya. He blamed the confusion on the difficulty of trying to stay abreast of the administration’s positions and on the timing of Obama’s call for the ouster of Libyan leader Moammar Gaddafi.

“If you had asked me, should we jump in the lake, I would have said no,” he said. “Once we jump in the lake, I say swim as fast as you can. There’s not a contradiction between saying let’s stay dry and let’s swim as fast as you can if in the intervening moment you’re in the lake.”

Most speakers took issue with an earlier statement by Indiana Gov. Mitch Daniels, another potential candidate, who has called for a truce on cultural issues because of the need to focus on what he sees as a looming fiscal crisis.

“I’m here to tell you that if you don’t start with values and you don’t start by establishing who we are as Americans, the rest of it doesn’t matter,” Gingrich said. “Life is not just about money.”

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