learn about this. as we report today, at the very least it suppose there was concern in the white house, and concern within president trump's legal team about, what manafort and flynn might tell mueller if they were to cooperate with the special counsel. there seems to be concern that mueller at this time, have been, was building cases against both flynn and manafort. if the two were to flip and cooperate, there seemed to be concern about what they might have to say about the president and the president's advisers. >> questions about pardons have also come up during interviews with the special counsel's investigators. >> that's right. and witness interviews in the last several months, mueller's investigators have asked various witnesses about conversations in the white house about pardons. we reported also that president trump raised the issue with the white house counsel's office sometime last year during which he asked about the pardon powers. he was asking about what authority does he have to