On his 500th day in office, Trump goes full dictator.

Trump commemorated his 500th day of occupying the Oval Office in true Trumpian fashion — with a rambling Twitter meltdown in which he declared his “absolute right” to pardon himself.

“As has been stated by numerous legal scholars, I have the absolute right to PARDON myself,” he tweeted, “but why would I do that when I have done nothing wrong? In the meantime, the never ending Witch Hunt, led by 13 very Angry and Conflicted Democrats (& others) continues into the mid-terms!”

His tweet comes one day after his attorney Rudy Giuliani said on ABC’s “This Week” that Trump “probably” has the power to pardon himself. Former U.S. Attorney Preet Bharara immediately shot that down, saying such a move would be “outrageous.”

But then, Trump has already used his pardon power in outrageous ways. Last week, he pardoned right-wing hate-monger Dinesh D’Souza, who pleaded guilty — and claimed to feel remorse at the time of his plea — for illegal campaign donations.

Last year, he pardoned his fellow birther, the criminally racist former sheriff of Maricopa County, Joe Arpaio.

In April, he pardoned Scooter Libby, the former aide to Dick Cheney who was involved in the outing of CIA agent Valerie Plame under the Bush administration.

Many legal experts have warned that Trump’s pardons appear to be sending a message to those involved, and even convicted, in the Russia investigation: If they protect Trump, pardons await them.

They have also said that using pardons in this way could certainly be an impeachable offense.

But last week’s talk of impeachment over his pardons hasn’t stopped him. Instead, he’s gone a step further, insisting on “absolute right” to simply pardon away any indictment or conviction of his own crimes.

That’s a terrifying notion. But it also shows how scared Trump and his team must be.

As part of his 500th day meltdown, he also declared that the mere appointment — by his own Justice Department — of special counsel Robert Mueller is “totally UNCONSTITUTIONAL.”

For all of his bluster, Trump’s increasingly unhinged rants and declarations reveal how worried he and his team must be about what’s to come. And that’s why he’s already warning of the extreme and unprecedented actions he’s prepared to take.