Transcript for Who is Robert Mueller's new boss?
here to the uproar over the forced resignation of attorney general Jeff sessions, and the appointment of sessions' chief of staff as a temporary replacement. His name is Matthew Whitaker, and he's been publicly critical of special counsel Robert Mueller's investigation in the past. Here's ABC's chief white house correspondent Jonathan Karl. Reporter: Tonight, amid a growing outcry over the president's appointment of a political loyalist to run the justice department, multiple sources tell ABC news Matt Whitaker will not recuse himself from overseeing the Russia investigation. And before joining the trump administration last fall, Whitaker made his views on that investigation perfectly clear. On the question of whether the trump campaign clulded with the Russians? The truth is, there was no collusion with the Russians and the trump campaign. There is not a single piece of evidence that demonstrates that the trump campaign had any illegal or even improper relationships with Russians. It's that simple. Reporter: And here's Whitaker on whether the president obstructed justice -- There is no criminal obstruction of justice to be had here. The evidence is weak. No reasonable prosecutor would bring a case on what we know right now. Reporter: Whitaker is now the acting attorney general, until a permanent replacement is confirmed. White house officials say Whitaker himself could be nominated. Other names on the short list include other staunch political supporters of the president. His personal lawyer, Rudy Giuliani, and Chris Christie, now an ABC news contributor, who ran the trump transition during the campaign. Christie told David he would consider taking the job. You always take a call from your president, no matter which party. And you listen to what he has to say. Jon Karl with us tonight from the white house. How long can Matthew Whitaker remain in his position as acting attorney general? Reporter: David, under a law known as the vacancy act, he can remain acting attorney general for up to seven months. But he is running the justice department at a critical time. ABC news has learned that special counsel Robert Mueller
This transcript has been automatically generated and may not be 100% accurate.