The speech offers her the opportunity to articulate the Republican Party's message at a time when most of the attention is on nearly a dozen candidates brawling for the GOP presidential nomination. And it serves as a test of whether Haley, the 43-year-old who is the first female and Indian-American to govern this Deep South state, might join that nominee later this year as a vice presidential candidate.
Haley has been prepping for hours every day. But she and her team are under no illusions that her delivery should try to compete with the President's.
"She recognized looking back and watching some of the other ones that that's a no-win situation. You can't compete with the pageantry of the President in the halls of Congress with the vice president and speaker," says her senior adviser Tim Pearson.
Haley is approaching this as an "opportunity to speak about the things that she cares about," Pearson said. Though he declined to provide more details, expect to hear about issues she's championed as a governor: economic growth in her state, education, and perhaps a line or two speaking to healing in light of the Charleston shooting.
In June, Haley found herself in the national spotlight when a self-proclaimed white supremacist opened fire on a Bible study class in Charleston, killing nine. Speaking the next morning in Charleston, the governor choked back tears as she declared that the "heart and soul of South Carolina was broken."
Haley is a key figure this election season. Her state's February 20 primary could be make or break for some Republicans vying to prove their conservative credentials. She hasn't endorsed anyone, but is also not keeping quiet, calling out GOP frontrunner Donald Trump over his proposal to temporarily ban Muslims from entering the United States, saying it was "absolutely un-American" and "unconstitutional."
"It defies everything that this country was based on and it's just wrong," Haley told reporters in December and adding later that the policy was "an embarrassment" to her party.
Rise in South Carolina
Haley has found plenty of fans -- and critics -- at home.
"I hope someone sees the wisdom of putting her on the ticket because I think this gift that she has would be great to share with the rest of the country," veteran GOP strategist Trey Walker, who worked for Haley in her early days in the governor's office, said outside of the Kemp Forum in Columbia on Saturday.
House Speaker Paul Ryan acknowledged the stakes are high for Haley's speech Tuesday night, but said she's a "natural."
"I'm really excited about this," Ryan told CNN's Jake Tapper on "The Lead." "If you want to hear an inclusive leader who's visionary, who's got a path for the future, who's brought people together, who's unified, it's Nikki Haley."
Even Democrats acknowledge she's a good messenger. "I think that she has the qualities that would make her a great press person. She can do sound bites and deliver her points like no one I've ever seen," said state House Minority Leader Todd Rutherford.
But Rutherford adds a stark warning -- one Republicans in Washington routinely cite when talking about the current occupant of the Oval Office. "When it comes to leadership, it simply has been lacking," he said. "I have worked with a Democratic governor at first and then a Republican governor, Mark Sanford. He would pick battles all the time but he would also invite Democrats to the governor's mansion to talk about issues. He would come to talk to our caucus meetings. She doesn't do any of that."
Republican strategist and former Mitt Romney adviser Kevin Madden says there is too much made of the audition part of the post-State of the Union speech and that instead the goal for any response is to do no harm.
"The main focus is play to your strengths, talks about your accomplishments, and offer interested viewers a vision for the future of the country," Madden told CNN. "Having a good performance helps but more importantly, Nikki Haley doesn't need this State of the Union address in order to be included in the VP conversation."
From Bamberg to the big time
Born in Bamberg, South Carolina, (population 3,600 in 2010) to Indian immigrants, Haley helped with bookkeeping at the family clothing store as a teenager and eventually got a degree in accounting from Clemson. She is married to Michael Haley, a National Guardsman who has served in Afghanistan, and has two teenage children.
Haley hasn't always been so self-assured. During a speech that she made at the National Press Club
last September, Haley told a poignant story of coming to terms with her own self-image. Though her parent's mantra was that people's similarities are greater than differences, she said her family struggled at times living as an Indian family in South Carolina.
"I remember being a child taking a test and being asked to check a box specifying my race. I didn't check white, I didn't check black, I checked 'other'," she told the Washington audience.
In 2004, Haley ran a long-shot campaign for the South Carolina House of Representatives in Lexington County, near Columbia, against the longest-serving member of the statehouse, a fellow Republican. She won the primary and won the seat.
Nathan Ballentine, one of Haley's longtime friends and current state representative, recalled their early years in Columbia after they defeated incumbent, establishment candidates.
"Nobody gave us a chance. Sadly it was like high school: nobody wanted to sit with us at caucus meetings. It was like we had the plague," Ballentine said.
He describes Haley as a "big ideas" person whose path you don't want to cross when she's got her mind set on something.
When they served together, Ballentine and Haley co-sponsored legislation calling for more accountability in on-the-record voting. It was not a popular measure and was voted down, but Ballentine says it spoke to Haley's style.
"She's still strong-willed," he says of her style then and now. "She has her allies, and it would be great if she had more that fought like her."
Haley has also faced -- and denied -- rumors and unproven allegations about affairs. In 2010, a former spokesman for Mark Sanford and current political blogger named Will Folks claimed
he had an "inappropriate physical relationship" with the governor several years prior.
Not long after Folks' claims, Larry Marchant, a South Carolina lobbyist and consultant, said he had a one-night stand with Haley during a conference in Utah in 2008. According to The State
newspaper, divorce lawsuit papers in 2013 between Marchant and his former wife inferred that he had an affair with Haley, but she was not mentioned by name.
Haley's deputy chief of staff Rob Godfrey provided this comment to CNN: "Nikki Haley ran for governor promising to give the people of our state a government they can trust that works for them, not the other way around. When you challenge the entrenched status quo, as the governor has, you make a lot of people mad and they do whatever they can to try to stop you, but that never stopped the governor during her first term, and it certainly won't stop her now."
In 2009, Haley launched another unlikely political campaign, this time for the governor's office. The primary race featured four contenders: it was three white men and Haley. She landed endorsements from Romney and Sarah Palin.
That primary race is famous in South Carolina politics -- political junkies love to discuss the turning points in the race that lead to her skyrocketing poll numbers just weeks before the election. She won the primary and then won again in the general, 51% to 47%. In 2014, she ran against the same Democratic opponent, Vincent Sheheen, and won again, this time with a margin of 55.9% to 41.3%.
When she was sworn in on January 12, 2011, she declared, "Today is a great day in South Carolina!" a line that has become somewhat of a catchphrase for her.
The Monday following the Charleston church shooting, Haley called for the Confederate flag to be removed from the statehouse grounds in Columbia. In the ensuing battle that played out on the national stage, the state legislature voted to remove the flag and alongside family members of the church shooting victims, Haley signed the bill into law. On a hot and humid July morning, the Confederate flag was removed.
Haley won her battle with grit and grace, but she faced criticism at home for her reactive, not proactive, stance. Sheheen, the Democratic state senator who lost to Haley in the 2010 and 2014 gubernatorial races, included the flag removal in his platform during both of his elections and it was his bill introduced in the statehouse that ultimately passed. Sheheen says the lead to remove the flag came from the legislature, not the governor's office.
"I think that real leadership occurs when something's not popular and taking the flag down after the massacres was popular. Before the massacres it was unpopular," Sheheen says of the episode. "Leaders should be in front, not following."
Godfrey and the governor's office is not interested in politicizing the matter. "We're going to leave past political disputes with Vince Sheheen where they belong -- in the past -- and we hope he'll do the same," he said.