Republican presidential hopefuls Nikki Haley and Ron DeSantis faced off in their last debate before the Iowa caucuses. The frontrunner, former President Donald Trump, still has not taken the stage with his rivals. Annmarie Hordern 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/quicktake/?hl=en