Donald Trump is about to get his first challenger for the GOP presidential nomination in 2024: Nikki Haley. Politico reports that Haley — the former South Carolina governor and ambassador to the United Nations — is expected to announce her presidential candidacy on Feb. 15. Her candidacy is something of a surprise, as she once said she would never run against Trump. Now? "It's bigger than one person," she told Fox News. "And when you're looking at the future of America, I think it's time for new generational change." Who is Nikki Haley, and what are her chances of actually being the Republican nominee? Here's everything you need to know:  Who is Nikki Haley? Haley is the daughter of Indian immigrants. (Her birth name was Nimrata Nikki Randhawa.) Her parents built a gift and clothing shop where she started keeping the books as a teenager. "My mom built a successful business. My dad taught 30 years at a historically Black college. And the people of South Carolina chose me as their first minority and first female governor," Haley said at the 2020 Republican National Convention. She was elected governor of South Carolina in 2011 — the first woman and first ethnic minority to hold the post — where she oversaw the removal of the Confederate battle flag from state capitol grounds after the massacre at a Charleston African Methodist Episcopal church in 2015. In 2017, President Trump made her America's ambassador to the United Nations. She left the post at the end of 2018. What's Haley's case for being president? She's calling for generational change. "I don't think you need to be 80 years old to go be a leader in D.C.," she said in that Fox News interview, a clear reference to the advanced ages of both President Biden and former President Trump. NBC News points out that Haley has a number of credentials: A former governor with national security experience who is the "rare member of Trump's cabinet who didn't get mired in scandal or controversy." And she benefits from her link to South Carolina, which holds one of the earliest — and most influential — presidential primaries. But in the battle for the GOP nomination, she may have one significant shortcoming: "She appears to have no calling card in the GOP culture wars" like Trump and another likely presidential contender, Florida Gov. Ron DeSantis (R). Why is Haley running against Trump? Trump seems to be wondering the same thing. Business Insider reports that after news emerged of Haley's likely candidacy, Trump shared an April 2021 video of her saying she wouldn't run against him in 2024. "I would not run if President Trump ran," Haley said at the time. So what changed? Time points out that Haley has a rather complicated history with Trump — "sharply critical" of him during the 2016 primaries, but then pivoting to serve in his administration. After the Jan. 6 insurrection, she suggested that Trump's political career was over: "I think he's lost any sort of political viability he was going to have." But then she flipped back a year later, telling The Wall Street Journal that "we need him in the Republican Party." Now she's running against him — but sought his blessing first. "I talked to her for a little while, I said, 'Look, you know, go by your heart if you want to run,'" Trump said. "She's publicly said that 'I would never run against my president, he was a great president.'" Is anybody else running? Not yet. The New York Times points out that the GOP presidential field has been slow to materialize: Nobody wants to take on Trump directly, "wary of becoming a sacrificial lamb on Mr. Trump's altar of devastating nicknames and eternal fury." Some possible candidates seem to hope that the justice system — prosecutors in New York or Georgia, perhaps — will take care of their Trump problem for them. In any case, there are a number of other prominent GOP names floating around as possible candidates. DeSantis is considered most likely, but Bloomberg reports that other possibilities include former Vice President Mike Pence, former Secretary of State Mike Pompeo, Sen. Tim Scott (R-S.C.), Virginia Gov. Glenn Youngkin (R), and several other governors.  What are Haley's odds of winning the GOP nomination? Not great at the moment. CNBC points out one recent poll showing that Trump leads a potential GOP primary field with 48 percent of the vote — while Haley comes in at just 2 percent. But the presidency may not be the real prize for Haley. New York's Ed Kilgore says there is a  "perception that she's really running for vice-president." (There were reports in 2020 that she was under consideration to replace Pence as Trump's VP pick.) The vice presidency might be "an acceptable consolation prize," Kilgore writes. After all, she's only 51. There are still a lot of possible presidential races in her future.