ABC News' Jonathan Karl and Amy Bingham report:
Rep. Michele Bachmann is proving to be a force to be reckoned with as she picks up momentum in early caucus states and surges in the polls.
A national Quinnipiac University poll released Wednesday showed Bachmann gaining on front-runner Mitt Romney, with 15 percent of likely GOP voters favoring her as the Republican nominee compared with Romney's 25 percent.
A similar poll in June showed Bachmann behind the former Massachusetts governor by 19 points. That gap has now narrowed to just 10 percentage points.
That puts her ahead of former vice presidential candidate Sarah Palin who was the top pick for just 12 percent of likely GOP voters.
Looking only at Iowa, a key first caucus state, the Minnesota congresswoman is doing even better. Three separate polls over the last week put Bachmann in first place.
"Republican primary voters are looking for somebody who brings some excitement, who brings something different to the table and she definitely does that," ABC News Political Director Amy Walter said.
While she has always had tough rhetoric, this newfound poll popularity has given her the authority of a top-tier contender for the Republican nomination.
Bachmann took aim at President Obama Wednesday, accusing him of "holding the full faith and credit" of the country hostage on the debt limit increase.
"We were all shocked and appalled that President Obama dangled out in front of the camera that senior citizens may not get their checks. That's a very dangerous statement to make," she said at a Wednesday news conference. "We don't believe that for a moment."
Bachmann announced Wednesday that she is co-sponsoring a bill with GOP Reps. Steve King of Iowa and Louie Gohmert of Texas that would prioritize spending to active-duty military if a deal was not reached in time to raise the debt ceiling.
On social issues Bachmann is taking an equally tough stance. She is one of two Republican presidential candidates to sign on to a "Declaration of Dependence on Marriage and Family" Marriage Vow.
Pennsylvania Sen. Rick Santorum has also signed the vow that asks candidates to outlaw pornography, vow faithfulness to their spouse and support a Constitutional amendment outlawing same-sex marriage.
The pledge came under fire earlier this week because of a sentence in the introduction suggesting that African-American children were better off under slavery.
Bachmann had been the subject of controversy before for slavery-related remarks she made as a Minnesota state senator. In 2004 she referred to people "involved in the gay and lesbian lifestyle" as being in "personal enslavement."
Her statements came soon after she introduced a state constitutional amendment to outlaw same-sex marriage in Minnesota.