Fox News correspondent-at-large Geraldo Rivera lashed out at President Donald Trump for his behavior since losing the election to President-elect Joe Biden.

In a tweet Saturday night, Rivera said he supported Trump for four years while the president was “assailed by leftist creeps who conjured the Russia Hoax to wreck his presidency.”

“Sadly he lost a bitterly contested election,” he said. “However since he has behaved like an entitled frat boy.”

Rivera has been a vocal supporter of the president. However, he has acknowledged since November that Trump lost the election, even as the president refuses to concede and continues to challenge the results.

On November 12, Rivera praised Trump for his time in office, but also said the time was coming soon for the president to “say goodbye with grace and dignity.”

For almost 4 years I’ve supported @realDonaldTrump who was assailed by leftist creeps who conjured the Russia Hoax to wreck his presidency. Nevertheless he prevailed. Sadly he lost a bitterly contested election. Shit happens. However since he has behaved like an entitled frat boy
— Geraldo Rivera (@GeraldoRivera) December 27, 2020

Trump and some of his allies have continued to deny the results of the election, even after the Electoral College vote confirmed Biden’s win. Instead they have launched a string of lawsuits, the vast majority of which have been dismissed.

During a Fox news appearance earlier this month, Rivera said Trump was damaging “the fabric of our democracy” by dragging out the election.

Rivera also took aim at conservative attorney and Trump advocate Sidney Powell in a separate tweet Saturday night.

In response to a tweet that said Powell will “burn the deep state down” with evidence, Rivera called her “pathetic.”

“Sidney Powell is a pathetic lawyer who among others is working to destroy the legacy of Donald Trump,” he said.

Powell has spread unsubstantiated claims about the election, including some about widespread voter fraud and voting machines “flipping” votes from Trump to Biden.

None of her legal challenges have held up in court, with judges dismissing her cases for a lack of evidence or standing.