President Donald Trump’s administration has enacted mass deportations for immigrants and is looking to end birthright citizenship for the children of some immigrants.

But can the president even consider revoking the citizenship of someone born in the U.S., even if they are a political foe?

Trump is attempting a unprecedented action, according to national news reports Saturday.

Shortly before 10 a.m., Trump said on Truth Social that “because of the fact that Rosie O’Donnell is not in the best interest of our Great Country, I am giving serious consideration to taking away her Citizenship.”

Trump called O’Donnell a “threat to humanity” and said she should stay in Ireland, where she moved to in January after Trump was sworn in for his second term.

The White House declined to comment to national media outlets on whether Trump was serious about the threat. There is no legal precedent for a president to revoke the citizenship of an American born resident.

O’Donnell lashed back at Trump with her own insults on Instagram. She claimed that Trump, whose administration has sought to curtail paths to citizenship, was planning to “deport all who stand against” his “evil tendencies.”

“The president of the USA has always hated the fact that I see him for who he is – a criminal con man sexual abusing liar out to harm our nation to service himself,” she said. “This is why I moved to Ireland.”

She also posted a picture that was taken of Trump with Jeffrey Epstein, taken in 1997 in Palm Beach, Fla.

O’Donnell claimed that she lives “rent-free” in Trump’s brain.

“You call me a threat to humanity –
but I’m everything you fear: a loud woman, a queer woman, a mother who tells the truth, an American who got out of the country (before) you set it ablaze.”

She added, “you build walls –
I build a life for my autistic kid in a country where decency still exists.”

Experts, quoted by The New York Times on Saturday, said that Trump has no power to take away citizenship of a U.S.-born citizens.

“U.S. citizens can relinquish their citizenship voluntarily, and federal courts can strip naturalized citizens of their citizenship if there is proven fraud or misrepresentation of other major cases,” Julia Gelatt, associate director of the immigration program at the Migration Policy Institute said to the New York Times. “But U.S.-born citizens cannot have their citizenship taken away.”

Trump and O’Donnell have been feuding since 2006, according to the New York Times. That year, the actress mocked Trump on “The View” for defending a Miss USA contestant who was roiled in controversy.

The rift continued as Trump was running for president in 2015. When asked by moderator Megyn Kelly about Trump’s use of language like “fat pigs, dogs, slobs and disgusting animals” to describe women, Trump replied, “only Rosie O’Donnell.”