“Maybe he could die?” she wrote on X.
Ms Coulter was previously one of Mr Trump’s most prominent supporters. In 2016, she endorsed the former president and authored a book, In Trump We Trust: E Pluribus Awesome!
However, she turned against the former president after accusing him of “betraying” his voters by failing to complete the much-touted wall along the US-Mexico border to stop the flow of undocumented migrants.
She has since been an outspoken critic of Mr Trump, describing him as “the biggest wimp ever to serve” and “a gigantic baby” who “can barely speak English”.
“The only reason he crushed in 2016 is because of immigration – the wall, deport illegal immigrants, the [Muslim] travel ban,” Ms Coulter said in August of Mr Trump.
She went on to praise his former GOP presidential nominee rival, Florida governor Ron DeSantis. “That is DeSantis this time – without the total lack of interest in carrying it out.”
Mr DeSantis ultimately dropped out of the presidential race last month after a distant second-place finish against Trump in the Iowa caucuses, meaning South Carolina governor Nikki Haley is now Mr Trump’s only contender.
Despite her praise of Mr DeSantis, Ms Coulter has opted not to officially pick a side in the GOP primaries, instead putting her energy into attacking anyone who doesn’t support a complete border overhaul.
Last year, she told Nikki Haley: “Go back to your own country.” Ms Haley was born in the United States.
Meanwhile, on Saturday, she once again criticised Donald Trump for his stance on immigration.
“Trump won’t close the border,” she claimed. “He’ll push for amnesty, allow anchor babies and sanctuary cities to continue, ban bump stocks, propose taking guns away without due process and hire half of Goldman Sacks,” she added on X, misspelling the name of the investment giant, Goldman Sachs. “The presidential election is worthless. Concentrate on the House & Senate.”
Mr Trump has pledged to build miles of more border wall and impose dramatic limits on asylum, and says he will revive a policy his administration used to require migrants to await their asylum hearings in Mexico.
The former president previously described Ms Coulter as a “has-been” and a “stone cold loser”.
The Independent has contacted Ms Coulter and Mr Trump for comment.