Tillis explained that he would not vote for any Fed nominee until a criminal investigation targeting the institution's current chair, Jerome Powell, is resolved. According to Powell, the investigation by the Washington federal prosecutor's office is politically motivated. He says he is being targeted for refusing to cut interest rates as quickly and as sharply as US President Donald Trump wanted.

Despite his current opposition, the senator said he had a favorable view of Kevin Warsh and was impressed by his skills. He added that he has known Warsh's work for a long time and regretted that he could not back his nomination until questions tied to the investigation involving Jerome Powell are clarified.