Graham said that Whitaker sees no need to recuse himself from the Russia probe after he made remarks openly hostile to the investigation prior to his appointment.
Graham told reporters that he doesn't think Whitaker is "going to do anything unsavory."
"I've a lot of confidence that Mr. Mueller will be allowed to do his job and that the legal process that was in place before Mr. Whitaker arrived will be followed," the senator added.
Whitaker drew the ire of Democrats following his appointment by Trump one day after the midterm elections because he had been openly critical of the Mueller probe, saying it goes too far in an opinion piece for CNN, calling it "fishy," and "ridiculous."
Nonetheless, Graham is convinced that Whitaker, who was the chief of staff to the attorney general at the Department of Justice prior to his appointment, will "honor regular order."
"I have every confidence he'll make reasoned decisions when his time comes and that the investigation is not in jeopardy," Graham added.