The former White House counsel to US President Richard Nixon has slammed Donald Trump on Twitter, saying the president makes the Watergate scandal "seem like a brief idyllic daydream".
John Dean added that while Mr Nixon may have been "corrupt", Mr Trump is "evil".
"History will treat Nixon’s moral failures as relatively less troubling than Trump’s sustained and growing decadence, deviousness and self-delusive behavior. Nixon=corrupt; Trump=evil," he tweeted on Sunday.
The Watergate scandal consumed and eventually brought down the Nixon presidency. It involved the break-in, and subsequent cover-up, of five men into Democratic National Committee headquarters at the Watergate office complex in Washington DC.
Mr Dean was a key figure in the scandal, referred to as the "master manipulator of the cover-up" by the FBI.
But he ended up testifying against his former boss and received a reduced prison sentence for his involvement.
Mr Trump is embroiled in an investigation that some say has the potential to bring down his presidency.
Richard Nixon in the White House. Source: Getty
Former FBI director Robert Mueller is investigating allegations that members of Mr Trump's campaign team colluded with Russia to sway the 2016 election in his favour.
The probe has expanded to examine possible attempts by Mr Trump himself to obstruct the investigation, which could - if proven - lead to the president's impeachment.
Donald Trump on the campaign trail for the US midterms. Source: AAP
But Mr Trump has called the probe a "witch hunt".
It comes just days before the US midterm elections, where US voters will determine who controls Congress, as well as picking new mayors, governors and state legislatures across the country.
