evidence: Nikki Haley, a former U.N. ambassador and governor of South Carolina now running for president, believes she's gaining momentum. Haley has said her campaign received a boost after her performance in the first Republican primary debate, last month, and a FiveThirtyEight/Washington Post/Ipsos survey also showed likely GOP voters gave her high marks based on what they saw. [...] Haley served in Trump's administration as the ambassador to the U.N. and later became the first major Republican candidate to challenge him when she launched her presidential campaign back in February, though she previously said in 2021 that she wouldn't do so.