Latest news from the 2024 presidential campaigns ahead of Iowa caucusesWith just a day to go before the Iowa caucuses, the candidates are braving subzero weather to deliver their closing arguments to caucusgoers.North Dakota Gov. Doug Burgum, a former Republican presidential candidate, endorsed Donald Trump at the former president’s rally. Marco Rubio's endorsement soon followed.Meanwhile, Sen. Joni Ernst, R-Iowa, who has declined to endorse a candidate a day before the caucuses, said on NBC News’ “Meet the Press” that she would not rule out backing Trump if he wins in the state, but she also called former U.N. Ambassador Nikki Haley “a great candidate.” Later, at a campaign event, she called Haley a "dear friend" and "inspiring leader." Trump has a nearly 30-point lead in the final NBC News/Des Moines Register/Mediacom poll before the caucuses. Meanwhile, Haley is narrowly ahead of Florida Gov. Ron DeSantis, with 20% to his 16%.While the majority of likely GOP caucusgoers say they would vote for Trump in the general election if he’s the nominee, regardless of whomever they support on caucus night, nearly half of Haley’s supporters say they would vote for Democratic President Joe Biden over Trump in a general election matchup.