his poll numbers go up, but his republican challengers are hoping to use trump's legal trouble to their advantage. jeff zeleny is in iowa. >> if i weren't leading fin the polls by so much, they wouldn't be indicting me. >> reporter: trying to use the indictments as a rally. >> i will never let them take away your freedom. >> reporter: the former president making clear he's consumed by the probe of his attempts to cling to power and overturn the results of the 2020 election. >> every time i get a subpoena, you know my polls go up, i get more and more subpoenas, report to a grand jury, he's killing biden. >> reporter: before his appearance in council bluff, said he would focus on a leading rival. florida governor ron desantis. >> he would be a total disaster,