April 2, 2012 -- There is a wooden sign posted on South Carolina Gov. Nikki Haley's statehouse office door: "Can't is not an option."
Haley has broken many barriers in the state. She is not only its first non-white governor, but also its first female and, elected at 38, its youngest. She touts the phrase as a defining idea for her administration. It is even the title of her new book.
At an interview at the governor's mansion in Columbia, S.C., Haley told "Nightline" the sign has been there since day one of her administration.
"I want everyone who comes in -- staff, legislators, constituents -- to know from the outset that's how things work here," she said.
It can make her a tough boss at times she admits, but, she says, an effective one.
Watch the full interview with Gov. Nikki Haley on "Nightline," Tuesday, April 3 at 11:35 p.m. ET/PT
A Tea Party favorite endorsed by Sarah Palin during her gubernatorial race in 2010, Haley's endorsement in the Republican primary was a highly coveted one. The South Carolina governor came out early for Mitt Romney, criss-crossing the state with him in the weeks before the state's January primary.
Despite her stalwart campaigning on his behalf, Haley claims she has no interest in being his running mate. If offered the vice presidential slot, Haley said she would not take it.
"I'd say, 'Thank you, but no,'" she said. "I made a promise to the people of this state. And I think that promise matters. And I intend to keep it."
But the governor fell short of delivering a South Carolina win to Romney. Instead the GOP presidential candidate suffered a substantial defeat in the Palmetto state, falling 13 percentage points behind Newt Gingrich.
Haley brushed off Romney's loss.
"South Carolinians are strong, independently-minded people," Haley said. "At the end of the day, they make their own decisions. And I respect them for that. And I welcome that. And I told him that from the very beginning."
Haley said she "can sleep at night" after his loss, because she still thinks Romney is "the one" who will get the nomination and is best positioned to beat President Obama.
She rejects the idea that her party is waging a "war on women," an accusation that many women's rights activists have levied at the Republican Party following its opposition to the government mandating that contraception be covered under insurance plans.
"The public likes to think that women only care about contraception," Haley said. "Contraception doesn't define a woman. That's -- doesn't define our views. We're so much smarter and broader than that."
The governor bristles at the thought of being called a "feminist," which she deems "a hard word."
"I think any label is bad," Haley said. "I'm more than a label. I am Nikki Randhawa Haley, who was born and raised in Bamberg, who is the proud wife of an officer in the military, and the very proud -- mother of two children.
"That's who I am," she added. "If you want to label me, label me that."
In a state where the confederate flag still flies at the state house, convincing Southerners to accept a young, female Indian-American as their governor proved challenging.
"I had a white senator call me a rag head, and I had an African-American legislator call me a conservative with a tan," Haley said.