His crushing lead over rivals appears unsurmountable and polls show Trump and US President Joe Biden facing off and in a dead heat. “I’ve been through the process, I’ve run four national campaigns over the years and seen it from that perspective. I’ve seen a lot of surprises over the years. We’ve seen others win the Iowa caucus on the Republican side and then disappear.”--With assistance from Laura Millan and Zoe Schneeweiss. Most Read from Bloomberg Businessweek©2024 Bloomberg L.P.