In an appearance on ABC breakfast show The View, the former US Secretary of State said a second Trump administration could be the “end of the country”.
Ms Clinton, who lost her 2016 presidency bid to Trump, told the show that she saw people as Secretary of State who would get elected and then “to do away with elections and do away with opposition.”
She said: “You could see it in countries where, well, Hitler was duly elected, right?
“And so all of a sudden somebody with those tendencies, so dictatorial authoritarian tendencies, would be like, OK, we’re going to shut this down.”
The Democrat added in a warning about a second Trump term: “Trump is telling us what he intends to do. Take him at his word.”
Her comments came days after a Washington Post report claimed Trump was discussing how to use the justice department to investigate political rivals if he is successful in reclaiming the White House.
Trump is currently tipped to be the Republican Party’s pick for 2024 Presidential candidate, despite being the only president in history to be impeached twice.
He is also facing a litany of court cases which threaten to take him off the 2024 campaign trail - and some which could even see him facing jail if found guilty.
In his civil fraud case in New York, Trump’s lawyers on Thursday asked judge to put an immediate end to the case, arguing that state lawyers had failed to prove that the former president intended to dupe banks with fraudulent evaluations of his business empire.
Trump's lawyers asked Judge Arthur Engoron to clear the 2024 Republican front-runner of wrongdoing.
“There's no victim. There's no complainant. There's no injury. All of that is established now by the evidence," Trump lawyer Christopher Kise said.
State lawyer Kevin Wallace responded that there was no basis for what's known as a directed verdict.
The judge did not make an immediate decision, but signalled interest in seeing the trial to its conclusion.
On the witness stand on Monday, Trump said if anything he had underestimated his wealth, contrary to the New York Attorney General’s claim that the Trump Organization used exorbitant estimates to attain favourable loan deals.
The former president’s lawyers are scheduled to start calling witnesses on Monday, although they would not need to do so if the judge gave a summary ruling in his favour.