stopped. let's bring in cnn chief political correspondent dana bash. dana, some critics are saying that this fight illustrates that jeb has a brother-shaped alba tras around his neck. >> this is one aides see more as a badge of honor than albitras. it's something that is rare this election year and welcome inside the bush campaign. a political duel about america's catastrophe on 9/-- donald trum tweeting i'm fighting to make sure it doesn't happen again. jeb is too soft. that after mush had tweeted donald trump talks about foreign policy as though he's still on the apprentice. at issue, trump's suggestions that jeb's brother george w. bush could have done more as president to prevent the september 11th terror attacks.