carolina, with tonight's debate. and katy, all the stuff surrounding cruz, will trump make an issue out of this, you think? >> reporter: he certainly already has. he said it was a very big thing, talking about cruz's loans, that he doesn't know much about it, but he hears it's a big thing. it's a similar sort of way that he's kind of attacked cruz in the past, especially around birth eerism but it's going to a big problem and there are a lot of questions. this is how he's been attacking cruz, sewing doubt in doubters' minds, saying that he has issues, that it's not going to be a sure bet if he gets the nomination, that he'll run into problems with either his eligibility or his finances, and it will be an issue for him in the general election. he's not attacking cruz directly. that's not going to work for him. the both of them, thankly, are vying for the same supporters, especially in iowa. there's a lot of crossover there. so a direct attack isn't something that's necessarily going to benefit him. he's often said that he is a