(CNN) John Dean, who served as White House counsel for President Richard Nixon during Watergate, said Monday that President Donald Trump has engaged in a "very public obstruction of justice."

"He (Trump), as I see it, has already exceeded everything that Nixon did," said Dean, who is also a CNN contributor, on Anderson Cooper's "AC360." "He's really much more intimately involved than Nixon ever was in the cover-up."

Trump lashed out at special counsel Robert Mueller's team over the weekend, as well as former FBI Deputy Director Andrew McCabe and former FBI Director James Comey, raising fresh speculation the President could seek to fire Mueller. The White House publicly denied Sunday that Trump would do so.

Trump on Monday continued his Twitter attack on Mueller, calling the ongoing investigation into Russia's interference in the 2016 election a "witch hunt."

A total WITCH HUNT with massive conflicts of interest! — Donald J. Trump (@realDonaldTrump) March 19, 2018

"A total WITCH HUNT with massive conflicts of interest!" Trump tweeted. He has frequently slammed the probe as a "witch hunt," dismissing it as a frivolous investigation launched by his political enemies seeking to delegitimize his election victory.

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