Former Trump allies who turned against him and now oppose his 2024 campaign

Bill Barr was regarded as one of Trump's closest allies and canniest officials during his 2019 to 2020 stint as attorney general.

He played a key role in fending off legal scandals that embroiled Trump, notably the 2019 release of Special Counsel Robert Mueller's report on Russian interference in the 2016 election.

In March, Barr changed course and published a memoir in which he was highly critical of his former boss, and said he had opposed Trump's bid to cling onto power after his 2020 defeat.

More recently, he criticized Trump's decision to take stashes to government record with him to Mar-a-Lago after leaving office, and in a scathing New York Post op-ed called on the Republican Party to move on from Trump after the midterms.

"Among the current crop of potential nominees, Trump is the person least able to unite the party and the one most likely to lose the general election," Barr wrote.

Mike Pence served as Trump's vice president, and played an important role in attracting the conservative evangelical voters who were a key part of Trump's support base.

But his refusal to help Trump's bid to overturn his election defeat in 2020, when he refused to block Joe Biden's certification, provoked Trump's fury.

Pence became a hate figure for hardline Trump supporters, some of whom chanted for his execution during the January 6, 2021, Capitol attack when Pence was forced to flee alongside other members of Congress.

Pence mostly declined to criticise Trump in the wake of the riot. But amid speculation he is considering a rival presidential bid to Trump's, has become more openly hostile.

"The president's words [on 6 January 2021] were reckless and his actions were reckless. The president's words that day at the rally endangered me and my family and everyone at the Capitol building," Pence said in a recent ABC News interview of Trump's behavior on Jan. 6.

As secretary of state, Mike Pompeo represented Trump's "America First" foreign-policy agenda of the world stage.

Like Pence, he's also rumored to be a potential 2024 rival to Trump. Though he hasn't criticised Trump by name, has issued a series of jibes apparently aimed at him.

"We were told we'd get tired of winning. But I'm tired of losing. And so are most Republicans," tweeted Pompeo after the midterms, flipping a 2016 boast by Trump that Republicans should see so much success under his leadership they'd get "tired of winning."

He's also addressed Trump's recent dinner with Kanye West and white nationalist Nick Fuentes, issuing a criticism of anti-Semitism.

"We stand with the Jewish people in the fight against the world's oldest bigotry," tweeted Pompeo.

Former New Jersey Governor Chris Christie was one of the first prominent Republicans to endorse Donald Trump when he launched his insurgent bid for the presidency in 2015.

But Christie was fired as the head of Trump's transition team after his 2016 victory, reportedly at the urging of Trump's son-in-law, Jared Kushner, whose father had been successfully prosecuted by Christie.

Christie is now a frequent critic of Trump on cable news shows, and has accused Trump of being a serial loser in the wake of the midterms.

"We all remember in 2016, he said, if he got elected, there was going to be so much winning and winning and winning and winning, they'd get sick of winning," Christie said on a recent discussion on ABC News, picking up on the same old comment as Pompeo.

"None of us knew at the time he was actually talking about the Democrats."

Stephanie Grisham served as White House press secretary under Trump, and as a top aide to First Lady Melania Trump.

Leaving the White House after the January 6 riot, she revealed damaging behind-the-scenes information about Trump in her October 2021 memoir, and is now frequent critic on Trump on cable TV.

She has said she feels remorse at having worked for Trump, whom she's described as a "conman," and has called for the GOP to distance itself from Trump in the wake of the midterm results.

"The Republican Party really needs to look within right now and decide, are we going to go with the voters, who hire us, or are we going to go with this one man Donald Trump?" she told CNN in November.

John Bolton served as Trump's national security advisor, pushing a hawkish strategy on threats from adversaries including Venezuela and Iran.

He turned against Trump shortly after leaving office, and in his 2020 memoir described the chaos and dysfunction of the Trump administration.

Bolton has also criticised Trump over the GOP's midterm failings, suggesting he could launch his own presidential bid to frustrate Trump's 2024 bid.

"There's one thing that would get me to get into the presidential race, which I looked at in prior elections, it would be to make it clear to the people of this country that Donald Trump is unacceptable as the Republican nominee," Bolton told NBC News recently.