Attorney General William Barr took a few moments to "grapple" with the question of whether the White House has suggested that he open an investigation into anyone.

Sen. Kamala Harris, D-Calif., asked Barr the question during his hearing before the Senate Judiciary Committee on Wednesday.

"Has the president or anyone at the White House asked or suggested that you open an investigation of anyone?" Harris asked.

"Um, I wouldn't — I wouldn't — Um," Barr replied.

After Harris asked, "Yes or no?", Barr asked her to repeat, which she did.

"Um, the president or anybody else —," he said before trailing off again.

"Seems you would remember something like that and be able to tell us," Harris said.

"But I'm trying to grapple with the word 'suggest.' There have been discussions of matters out there that they have not asked me to open an investigation," Barr said. '

[Watch: Barr testifies about Mueller investigation before Senate Judiciary Committee]

"I'm trying to grapple with the word 'suggest'." pic.twitter.com/WZ2LB6jwbv — Josh Marshall (@joshtpm) May 1, 2019

Harris offered: "Perhaps they've suggested." Barr dismissed the notion.

"Hinted?" Kamala asked. Barr said he didn't know.

"Inferred? You don't know? OK," Harris said before moving on to another topic. Barr tried to suggest something, but Harris shot him down, saying, "Sir, I'm asking a question."

Harris, a former attorney general of California, is a 2020 candidate for president. During her line of questioning, Harris also got Barr to admit that he decided not to charge President Trump with obstruction of justice without seeing the underlying evidence of special counsel Robert Mueller's Russia investigation report.

After leaving the room, Harris told reporters that Barr "lacks all credibility" and called on him to resign.