John Dean, former President Richard Nixon’s White House counsel, suggested Wednesday that Attorney General William Barr lied to Congress during his testimony earlier in the day.

“Barr did more than stammer, I suspect. Maybe lie?” Dean tweeted. “[It] is difficult to imagine that Trump has not asked his AG to go after his enemies, like Hillary, and others.”

“It feels to me like we are back in Nixonland!” 

Barr did more than stammer, I suspect. Maybe lie? If is difficult to imagine that Trump has not asked his AG to go after his enemies, like Hillary, and others. It feels to me like we are back in Nixonland! https://t.co/ncJdTds7uW

— John Dean (@JohnWDean) May 1, 2019

Dean’s comment came in reference to Sen. Kamala Harris’s (D-Calif.) questioning of Barr during his testimony to the Senate Judiciary Committee, during which she asked Barr if President Trump had asked him to launch investigations of anyone, to which Barr asked her to repeat the question. 

{mosads}Dean, who became a key witness for the prosecution in the Watergate scandal after he pleaded guilty to obstruction of justice, shared a tweet from CNBC’s John Harwood that read: “When @SenKamalaHarris asked Barr if Trump or WH aides had requested that he launch investigations of anyone, Barr stammered.”

Barr faced questions from lawmakers on Wednesday about his handling of special counsel Robert Mueller‘s report on the investigation into Russian interference in the 2016 election.

In a line of questioning from Harris, a 2020 presidential candidate, Barr admitted that he did not review Mueller’s underlying evidence before concluding that Trump did not obstruct probes into Russian election meddling.

Pressure on Barr has risen after it was revealed Tuesday that Mueller expressed frustration to the attorney general about his four-page summary of the Russia probe sent to Congress in late March. 

Barr said Wednesday that he would not return for a planned Thursday testimony in front of the House Judiciary Committee, after committee Democrats failed to reach a deal with the Justice Department on the format of the questioning.