I spoke with Rep. Michele Bachmann (R-Minn.) the day after CNN’s foreign policy debate. Her aides looked worn after a slew of 18-hour days, but she was fresh and cheery. Her only immediate worry was getting out of the District and back to Minnesota for Thanksgiving. The highlight after dinner, she said is “turkey bingo” with gifts selected by her husband. That and Christmas Day will be her only breaks until the Iowa caucus on Jan. 3.

But Bachmann is no complainer. She said, “I defend the process [that] you must run the gauntlet.” She thinks candidates needed to be tested ( “have the snot knocked”out, as she puts it) in order to prepare for the rigors of the presidency.

Bachmann in person, after months on the campaign trail, is serious and focused. Again and again, she emphasized the seriousness of the challenges facing the country. “One thing we see more and more is that voters are starting to realize dealing with national security is the number one job of the president. This is not about entertainment. This is not a game show.” And in fact, considering the policy gaffes and shortcomings of her opponents, she comes across, in contrast to the pre-race conventional wisdom, as one of the candidates at the grown-ups’ table: knowledgable, articulate, focused and sober-minded.

She is also a fighter, and she knows all too well that that among her biggest challenges in Iowa is Newt Gingrich, who sits atop a number of national polls. She pulled no punches, ticking off a list of objectional positions.

Not surprisingly, she starts with Gingrich’s debate comments on illegal immigration. “It’s not going to work” with conservatives and in Iowa elsewhere. She also noted, “These are comments the speaker has made before.” She translated his plan as “11 million illegal workers should be made legal.” She add that Gingrich supported the DREAM Act (in the debate Gingrich said he approved of the portion that granted citizenship to those serving in the military). She continued, “He got a D minus” from an anti-illegal-immigration group. (This is NumbersUSA, which gave her the highest grade among GOP presidential candidates, a B minus.) She said emphatically, “I am the consistent conservative.”

She doesn’t stop there. She asserted, “He is the author of the individual mandate.” (Gingrich claims he got the idea from Heritage, but he was certainly an early champion.) She was just warming up. “On TARP he was for the $700 billion bailout while I was working to vote it down — until the Republicans caved.” Next, she recalled, “Newt sat on the couch with Nancy Pelosi. I remember him talking to a group of us in Congress. He said, ‘We’ve lost this issue.’” And then there is Freddie Mac. “He was paid $1.6 to $1.8 million to influence senior Republicans. I was fighting to put [Freddie and Fannie Mae] into receivership.”

She is behind in the polls, but her staff contends that Iowa polling is notoriously unreliable and that people are still making up their minds. She says with breezy confidence, “We are getting our message out. Now it’s a matter of getting our people out.” That’s a purposeful reminder that she has supporters and organization on the ground. (Gingrich and others, such as Herman Cain, have practically none.) She is philosophical about her decline in the polls: “Like Wall Street, the candidates have risen and fallen.” She said: “They [GOP voters] went to shop around. They’ve been shocked. Now I think they’ll come home.” She is confident: “They know who Gingrich is and his variance on the issues.”

Gingrich was notorious in Congress for his lack of organization, discipline and leadership. Bachmann paints a contrast to her own life. As far as organization and discipline, she argued, “I’ve demonstrated that all my life. I ran a home with 28 kids. [Earlier in life] we fell below the poverty line, and I got through college and law school. I built a successful company. I brought about an educational reform movement in Minnesota, in what is arguably the most difficult state” to take on teachers’ union and the educational establishment. She continued with her list of accomplishments: “I ran in the worst year in 2006,” when Republicans were bleeding support and withstood an avalanche of Democratic money. “Nancy Pelosi spent $9.6 million.” As for her time in Washington, she said, “Once I got here I continued to fight and advocate” for those fed up with the federal government’s irresponsibility. “I was a messenger,” she said. “I led 40,000 people opposing Obamacare to D.C.” She made a thinly veiled reference to Gingrich’s penchant for compromise: “ When I was in the lion’s den I didn’t succumb. I just fought. I know how to do that. I know how to take complex policy matters and explain them.” And if that weren’t enough, she cited her organization and focus in “handling hundreds of complex cases” as a tax litigator.

Bachmann is candid. As many candidates will tell you, she said that running for president is “the hardest thing I’ve ever done.” And then matter-of-factly she says, “Before that was when I had a 2-year-old, a 4-year-old, a 6-year-old I was teaching to read — I was home schooling — a 7-year-old and four [foster] teenagers.” She says such things without hint of self-pity or boastfulness. It’s just what she did — no big deal, but evidence of her determination and skill.

Bachmann, as she did when I interviewed her in her Capitol Hill office in the spring, surprised with her steely determination and sober analysis of her competitors and a range of national security issues (which I will recap on Sunday in Part 2 of the interview). You expect flamboyance or rhetorical excess; instead she offers details and reasoned arguments. The challenge for her in the weeks leading up to the Iowa caucus is to let voters see that Michele Bachmann, draw a contrast with her — to be blunt — flaky competitors who are appealing to the same electorate, and convince conservative voters that others are flashes in the pan while she’s the real deal. I would say that’s all improbable, but Bachmann’s life is one improbable chapter after another. You’d be foolish to count her out.

In Part 2 on Sunday, Bachmann talks about foreign policy, the supercommittee, the debt-ceiling negotiations and the defense budget.