President Trump hopped on Twitter ahead of testimony from John Dean, to unleash a scathing tirade against former White House counsel for President Nixon, who was front and center of the now infamous Watergate scandal.

"The Dems were devastated — after all this time and money spent ($40,000,000), the Mueller Report was a disaster for them," Trump tweeted Sunday evening.

"But they want a Redo, or Do Over. They are even bringing in @CNN sleazebag attorney John Dean. Sorry, no Do Overs — Go back to work!"

Dean, who is now a regular CNN contributor, delivered televised testimony before lawmakers that helped lead to Nixon’s resignation.

He told CNN that he is unbothered by Trump's words:

“He’s called me nasty names before,” Dean said. “It doesn’t bother me in the slightest.”

Democrats in the House Judiciary Committee will quiz Dean on Monday over the controversial details in Special Counsel Robert Mueller's report - which did not exonerate the president and called for further investigation.

Back in January 2018, Dean compared the Russian election interference to the burglary at the Watergate office complex in 1972 that began the Watergate scandal during an appearance on CNN. He said presidential efforts to frustrate investigators in both cases could be considered obstruction of justice.

The Democrats have been considering impeaching Trump, and even Conservatives know that a Dean inquiry could be the beginnings of the writings on the wall.

According to Fox, "nothing says impeachment like Watergate and nothing says Watergate like John Dean."