The race to fill late 71-year-old Lindsey Graham's Senate seat is getting vicious after his sudden death.

The longtime senator and close Donald Trump ally unexpectedly passed away on Saturday night due to a 'sudden' heart complication. 

And it's set off a ferocious succession battle - with the President himself weighing in.

Trump announced in a Truth Social post on Monday that he hoped to see Graham's sister fill the vacant seat, and she was formally selected to serve on an interim basis on Thursday afternoon.

'I recommended, to Governor Henry McMaster, Lindsey Graham's wonderful sister, Darline, to serve as interim Senator from the Great State of South Carolina,' the President wrote on social media.  

'This would be a fabulous tribute to Lindsey, who loved her dearly!'

South Carolina is likely to have two replacements for Graham in the next six months - one appointed by the governor to serve out the months remaining in his term and another election to permanently fill the position for the next six years. 

A top Fox News host has already taken his name out of the running for the role, but others - including embattled MAGA firebrand Congresswoman Nancy Mace - are considering bids for the position.

But White House insiders tell the Daily Mail that Mace's chances are slim after her weak fifth-place finish in the state's gubernatorial primary last month. 

Senior officials are opposed to Mace succeeding Graham and would raise money against her should she defy them, according to a Trump source.

The insider said plainly: 'She would be a total disaster.' 

Former congressman Trey Gowdy, who now hosts Sunday Night in America on Fox News, told the Daily Mail through a spokesman that he has not had any conversations about the open Senate seat and does not have any interest in it. 

Gowdy represented South Carolina's 4th Congressional District from 2011 to 2019, and held chairmanships of the House Oversight and Government Reform Committee and the House Select Committee on Benghazi during his tenure. He was also a prominent member of the House Judiciary Committee.

Senator Tim Scott of South Carolina floated Gowdy, Graham's sister Darline Graham Nordone and former Senator Jim DeMint as three people who he could see fill the seat on an interim basis during an interview on CBS Monday morning.

'I will say I hope that the governor will put a placeholder and let the voters decide. So I think in the next several hours or next day or so we will figure out who that person is,' Scott told CBS host Gayle King on Monday.

McMaster followed Trump's suggestion and tapped Nordone, making his official announcement on Tuesday afternoon in Columbia.

In a post on X made after Trump's nod, Scott shared that he came to the conclusion 'after speaking with Darline, there is no one better who understands Lindsey's love for family, our state, and our country.'

Scott had also mentioned Gowdy as a potential pick in a separate interview with Fox News, and Politico additionally reported that he 'made a round of calls supporting Gowdy,' while adding that McMaster is likely to go in a different direction. 

The field of candidates likely to run in the August 11 special primary includes South Carolina lieutenant governor Pamela Evette, who came in second to Wilson in the gubernatorial primary runoff last month.

A longtime Evette adviser told the Daily Mail that she is still deciding whether or not to enter the race, but confirmed that she has fielded calls from both in-state and national leaders who would like to see her continue to serve the state of South Carolina in government. 

Two South Carolina members of Congress who lost in the primary, Mace and Ralph Norman, have also indicated their interest in running for the full term.

A spokesman for Mace's campaign told the Daily Mail that 'Lindsey Graham was a mentor to Nancy Mace, and one of the funniest, quickest people she ever served alongside. Anyone who knew him knew he loved a good line, and told more of them than anybody in Washington.'

On Sunday, Mace posted a clip of the character Michael Corleone in The Godfather: Part III, captioned with the quote 'Just when I thought I was out… they pull me back in…'. The idea of Mace running for office again was not well-received by conservatives.

Responding to the criticism, her spokesman added, 'When she posted that quote, it wasn't a campaign wink. It was said with affection, from someone who knew him well enough to know he'd have laughed first and loudest.'

In a three-week primary sprint, Evette would bring significant statewide name ID and a projected floor of 30 percent support, which could prove critical to victory on such a short timeline.

The vacancy for South Carolina's Senate seat was created by Graham's unexpected death, which was announced just after 2am Eastern time Sunday morning.

Per a statement issued by his office just before 5pm that day, 'aortic dissection due to arteriosclerotic cardiovascular disease,' was the cause of death.

'The death certificate will be PENDING until all the toxicological and microscopic testing are finalized, and at that point the death certificate will be updated to reflect the cause of death and appropriately classify the manner of death,' Graham's spokesman added.

A 911 call for 'cardiac arrest' was placed from Graham's residence around 8.30pm on Saturday evening.