Trump used a rally to point to polls showing him well ahead of Florida governor and former vice president Mike Pence in the race to be the next Republican presidential nominee. He said: “Trump at 71 percent. Ron DeSantimonius at 10 percent. Mike Pence at seven… Oh, Mike’s doing better than I thought.” The clash with Mr. DeSantis appeared to fire the starting gun in a potentially tough Republican primary showdown as the party begins to look beyond Tuesday’s midterms to the next presidential election cycle. It drew immediate backlash from allies of Mr. DeSantis, who privately expressed their distaste for Mr. Trump. Several reportedly told Mr. DeSantis, 44, to move forward with an expected presidential run.