A former deputy attorney general for Virginia told Hill.TV that John Dean’s congressional testimony this week shows the public is looking to measure President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE's actions up against the Nixon administration's during the Watergate scandal.

“People are looking for some barometer for which to measure the president’s actions,” said Stephen Cobb, who also served in the Obama administration, during an interview Tuesday. “For some, they keep harkening back to the times of Nixon, so they want to bring somebody in who can say, 'This is better, this is worse, this is similar.'”

Cobb pushed back against conservatives who have questioned the legitimacy of Dean’s testimony.

“It’s not an issue of legitimacy,” he said. “No one was bringing in John Dean to be a legal scholar. They’re saying, 'How does the actions as outlined in the Mueller report compare to what you saw in the Nixon administration? Should we be holding this president to the same standards that Congress held you to in the 70s?'”

Democrats on the House Judiciary Committee this week began their hearings on special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE’s report.

Dean, a known Trump critic and key witness in bringing down President Richard Nixon, was approached for testimony to help explain key details from the Mueller report.

During the nearly four-hour hearing on Monday, Dean said the Trump administration is “in fast competition with what happened in the Nixon administration." He also compared the Mueller report to the Watergate “road map” that led to the end of Nixon’s presidency.

Trump later hit back, criticizing the former Nixon White House counsel for his remarks.

“John Dean’s been a loser for many years,” Trump told reporters on Monday.

—Tess Bonn