Florida Gov. Ron DeSantis, who entered the Republican presidential primary as Donald Trump's greatest threat, announced Sunday he is ending his White House bid nearly a week after his underwhelming performance in Iowa. In a video on X, DeSantis said there was no clear path to presidential success for his campaign. "If there was anything I could do to produce a favorable outcome, more campaign stops, more interviews, I would do it, but I can't ask our supporters to volunteer their time and donate their resources if we don't have a clear path to victory. Accordingly, I am today suspending my campaign," DeSantis said. "Winston Churchill once remarked that success is not final, failure is not fatal. It is the courage to continue that counts. While this campaign has ended, the mission continues down here in Florida. We will continue to show the country, how to lead. Thank you and God bless." It's a devastating blow to the promising career of a once-rising GOP star, and his failure to reach the lofty expectation of his candidacy has already sparked a wave of second-guessing from close allies and advisers. Some believe DeSantis took too long to attack Trump. Others think his team underestimated former South Carolina Gov. Nikki Haley. More remain convinced that there was nothing DeSantis could have done to wrestle the party from Trump's loyal and sizable followers. Also Trump defended his mocking of GOP rival Haley's given name, telling Fox News in an interview that aired Sunday that it's "a little bit of a takeoff on her name ... wherever she may come from." Haley is the daughter of Indian immigrants and was born Nimarata Nikki Randhawa. She has gone by "Nikki" since her childhood and took her husband Michael Haley's last name after they married. Trump first referred to Haley's first name by misspelling it as "Nimrada" in a post to his social media platform Truth Social last week and later referred to her as "Nimbra," in the latest examples of him using racist dog whistles to attack his opponents. "I do that with a lot of people, like (former Arkansas Gov. Asa) Hutchinson. I mean, he was polling at zero for one year, and I called him — rather than Asa, I called him Aida Hutchinson, and it just felt good to me," Trump told Brett Baier during an interview on the sidelines of his rally in Manchester on Saturday. During the interview, Trump also responded to Haley's claim that the name-calling is a sign the former president feels threatened by her, arguing he's "not concerned with her at all." Meanwhile, as New Hampshire primary approaches, here's a look at the participation rules for Republican nominating contests between now and the end of March. Thirty-six states and territories will hold Republican nominating contests between New Hampshire on Tuesday and Louisiana on March 23. Of those, 11 are closed, meaning only registered party members can participate (although some allow party switching on the day of the contest), and 22 are either open to all voters or semi-open, meaning that Republicans and unaffiliated voters can participate. In many states with open primaries, voters don't formally register with a party with the state. Information for three contests isn't currently available. While the early states are important for building momentum, the bulk of the delegates will be awarded in March. By the end of Super Tuesday, on March 5, 1,205 of the Republican convention's 2,429 delegates will have been awarded, or 99% of the 1,215 needed to win the nomination. — CNN