Donald Trump's chief rivals for the Republican nomination, Ron DeSantis and Nikki Haley, leave Iowa with little chance of successfully challenging the former president’s lead. Bloomberg's Gregory Korte reports. -------- Follow Bloomberg for business news & analysis, up-to-the-minute market data, features, profiles and more: http://www.bloomberg.com Connect with us on... Twitter: https://twitter.com/business Facebook: https://www.facebook.com/bloombergbusiness Instagram: https://www.instagram.com/bloombergbusiness/