subject at one hour doesn't mean that their status couldn't change and they couldn't become a target at another hour. is there some concern that there's something that could transspire in the course of an interview that could change the president's status? >> well, sure. so he could admit truthfully, which seems unlikely, his role in certain events, including an obstruction of justice. or you can just become a target having been a subject because the prosecutors and investigators learn more about you as time rolls on. these are all categories in which -- and in which people do and can shift. the fact that you're a subject one day, noik coal, certainly doesn't mean you can't be a target the next. that can come out of your own