President Trump has tapped yet another Fox News personality for political appointment, naming a former Westchester County district attorney and elected judge, Jeanine Pirro, as interim United States attorney in Washington, D.C.

The move came just hours after Mr. Trump had pulled his nomination of a conservative activist, Ed Martin Jr., after pushback from Senate Democrats and key Republican leaders for his lack of prosecutorial experience. In a post on Truth Social announcing the replacement appointment, Mr. Trump described Ms. Pirro as “a powerful crusader for victims of crime” and touted her career in television.

“Jeanine is incredibly well qualified for this position, and is considered one of the Top District Attorneys in the History of the State of New York. She is in a class by herself,” Mr. Trump said in the announcement.

Ms. Pirro is the latest in a string of appointees tapped from the Fox News well, including Secretaries Hegseth and Duffy. Ms. Pirro immediately resigned from her role as co-host of “The Five” upon news of her new appointment.

“Jeanine Pirro has been a wonderful addition to The Five over the last three years and a longtime beloved host across Fox News Media who contributed greatly to our success throughout her 14-year tenure. We wish her all the best in her new role in Washington,” a Fox News representative said in a statement to the Associated Press.

Ms. Pirro has long been a close ally of Mr. Trump, who in one of the final actions of his first term in the White House issued a pardon to her husband, who had decades earlier been convicted of tax evasion.

Ms. Pirro was also named as a central figure in a defamation lawsuit against Fox News by Dominion Voting Systems. The election machine and technology company accused Fox and several of its personalities, including Ms. Pirro, of disseminating unfounded claims that the firm attempted to influence the presidential race in favor of President Biden over Mr. Trump in 2020.

The reshuffling comes after a Republican senator, Thom Tillis of North Carolina, said he informed the White House that he would not support Mr. Martin’s nomination in the Senate after his temporary appointment expired. He told reporters that he made the decision due to the appointee’s defense of January 6 rioters.

“We have to be very, very clear that what happened on January 6th was wrong,” Mr. Tillis said. “It was not prompted or created by other people to put those people in trouble. They made a stupid decision, and they disgraced the United States by absolutely destroying the Capitol.”

The senator’s opposition would have prevented an advancement in Mr. Martin’s nomination and signaled that he might not have had enough votes to win confirmation.

Mr. Trump said in a subsequent post on Truth Social that Mr. Martin had done “an AMAZING job” and that he would be moving to multiple roles at the Department of Justice as the new director of the Weaponization Working Group, associate deputy attorney general, and pardon attorney. “In these highly important roles, Ed will make sure we finally investigate the Weaponization of our Government under the Biden Regime, and provide much needed Justice for its victims,” he said.