Her crusade against transgender bathroom access has cemented her role as a hardline culture warrior and MAGA favorite.
But an eye-popping video unearthed exclusively by DailyMail.com suggests that U.S. Rep Nancy Mace wasn't always as uptight about personal boundaries.
The lurid clip shows Mace, 47, downing a shot of liquor before locking lips with a spikey-haired female friend and dribbling it into her mouth.
The gal pal, wearing a Trump T-shirt, uses the same revolting technique to relay the booze to a male reveler.
He barely manages to spit it into the mouth of the next participant before violently retching and throwing up on the kitchen floor.
The final recipient is a queasy looking woman who clutches her mouth and struggles to swallow as the gross drinking game, set to blaring hip hop music, concludes.
DailyMail.com understands the boozy episode was filmed while twice-divorced Mace was campaigning for Donald Trump's 2016 Presidential campaign.
It was leaked to social media when she ran for the South Carolina State House in 2017 prompting Democrat opponent Cindy Boatwright to brand her immature and 'totally unfit' for public office.
South Carolina congresswoman Nancy Mace can be seen downing a shot before dribbling it into another woman's mouth, in an eye-popping video unearthed exclusively by DailyMail.com
DailyMail.com understands the boozy episode was filmed while twice-divorced Mace was campaigning for Donald Trump's 2016 presidential bid. Mace locks lips with a female friend, wearing a Trump t-shirt
The mom-of-two won the seat regardless and her star continued to rise when she was elected to Congress three years later.
Reached for comment, Mace didn't dispute the authenticity of the video but said it was taken nearly a decade ago, well before she entered Congress.
'This is why good people don't run for office,' she remarked.
But Boatwright insisted that nothing she had seen from Mace had altered her view that she was unfit for office.
'She is the worst sort of politician, an opportunist who is solely interested in her fame,' Boatwright told DailyMail.com
'She wants to be known as National Nancy.'
Fast forward to 2024, and Mace is rarely out of the news – most recently for introducing a resolution to stop trans Rep.-elect Sarah McBride from using women's bathrooms in the Capitol building.
The combative pol posted about the restroom issue more than 300 times in three days, labeling trans people 'mentally ill' and describing McBride as a 'man in a skirt'.
The female friend then uses the same revolting technique to relay the booze to a male reveler
The stomach-churning party game ended with the final recipient, a queasy looking woman who clutches her mouth and struggles to swallow
But critics pointed out that Mace had previously positioned herself as a moderate and as recently as July 2023 declared in a TV interview that she was 'pro-transgender rights'.
In 2021 she co-sponsored the Fairness for All Act which sought to ban discrimination based on gender and sexual orientation, saying her position was informed by 'having been around gay, lesbian and transgender people … over my lifetime.'
'Nancy has always been vocally pro-gay which makes her swing to the right on the transgender issue all the more puzzling,' a former friend told DailyMail.com.
'She had several gay friends and has told stories about going to gay bars with them. She's especially comfortable around gay women.
'As you can see in the drinking video, Nancy is certainly not some sort of ultra-conservative prude.'
Another close acquaintance doubted whether Mace's sudden reinvention as a right-wing firebrand was sincere.
'She craves attention above everything else,' the source scoffed.
'Her thirst to be in the news is what is motivating this latest escapade.'
Mace's hardening rhetoric has also coincided with multiple bust-ups with her Congressional staff, DailyMail.com has learned.
The lawmaker's offices in South Carolina and Washington, D.C. are said to have suffered an exodus of staffers since 2023 amid complaints about her erratic behavior.
One disillusioned senior aide quit to become a ski instructor while several others are said to have sought therapy after walking out.
'Huge doesn't even come close to describing it. We are talking about a 100 percent turnover in D.C.,' dished a former aide.
'Nancy would send profanity-laden messages. She would drop the F-bomb. She would make people cry.
Mace has become a Republican firebrand who has made headlines most recently for introducing a resolution to stop trans Rep.-elect Sarah McBride from using women's bathrooms in the Capitol building
Delaware Democratic Rep.-elect Sarah McBride is the highest-ranking elected trans politician in U.S. history
Mace turned 47 on December 4 and posted a celebratory picture of herself eating a pink taco – saying it was 'on brand'
'You could be absolutely berated at any given time.'
The ex-staffer traces the implosion to a fanciful rumor that began circulating in summer 2023 suggesting Mace was under consideration to become Trump's running mate.
Mace condemned the former President over the January 6 riot but the pair patched up their differences and she endorsed him in the 2024 Republican primary.
'I think the illusion of becoming Vice President caused her to shift her ideology,' the source reflected.
'The biggest shame of all is that if she just trusted people and stayed true to her values she would be unstoppable.'
The daughter of a United States one-star general, Mace grew up on military bases and was the first woman to graduate from The Citadel, the storied South Carolina military college, in 1999.
She has worked in real estate and previously ran a PR firm that boasted leading Republicans such as Tim Scott and former White House Chief of Staff Mick Mulvaney as clients.
Mace made a run at the Senate in 2014 but lost to Lindsey Graham in the primary before becoming a social media director for the Trump 2016 campaign.
Last month, Mace issued a brutal verbal takedown to a transgender activist who confronted her over her campaign to ban transgender women from using women's bathrooms on Capitol Hill
After representing the 99th district in the South Carolina House from 2018 to 2020 she beat Democrat incumbent Joe Cunningham to become the first Republican woman to be elected to Congress from the Palmetto State.
Mace notably teamed up with Matt Gaetz and six more GOP rebels in the headline-grabbing 2023 ouster of former House Speaker Kevin McCarthy.
And last month she took aim at incoming Delaware Democrat McBride who became the first openly transgender person to be elected to the US House of Representatives.
When Speaker Mike Johnson agreed that lawmakers must use the bathroom that corresponds to their biological sex, Mace went further by filing another bill that would apply to all federal buildings and federally funded schools.
'Oh, you thought threatening me would silence me?' she declared on X, formerly Twitter.
Mace doubled down by launching a provocative new line of merch adopting a women's bathroom sign as a battle logo.
That's despite telling CBS last year that, while she stopped short of supporting transgender surgery in kids, she was happy to see young people exploring their gender identities.
'If they want to take on a different pronoun or a different gender identity or grow their hair out, or wear a dress or wear pants, or do those things as a minor, those are all things that I think most people would support,' Mace said.
Mace shares custody of her own two teenage kids with her second husband Curtis Jackson, a 53-year-old software developer from Charleston. The couple's 14-year marriage ended in 2018
The D.C. property Mace owned with her ex-husband has been a source of further controversy over claims that the Republican misused a taxpayer-funded reimbursement program to recoup $23,000 from the cost of living there
'Be who you want to be but don't make permanent changes as a child.'
Mace shares custody of her own two teenage kids with her second husband Curtis Jackson, a 53-year-old software developer from Charleston.
They married in 2004 but the 14-year marriage ended in 2018 and they divorced a year later, neither party demanding alimony or spousal support.
Prior to that, Mace was wed to Chris Niemiec, 47, a former Citadel classmate and college sweetheart, for two years.
She got engaged to South Carolina entrepreneur Patrick Bryant in May 2022 but called things off 18 months later after discovering that he had a Tinder account.
Bryant told DailyMail.com at the time that it was an old profile and he had simply accessed the site long enough to delete it so it wouldn't show up on internet searches.
Their split triggered a messy legal fight over two pricey properties the ex-couple jointly purchased, one in South Carolina's exclusive Isles of Palms, the other close to her D.C. office.
The six-bed Lowcountry home they had hoped to turn into a luxe beachfront rental is back on the market at $4.8 million after a lawsuit was filed by Mace but quickly settled in mediation.
The D.C. property, meanwhile, was the source of further intrigue when a report suggested Mace may have misused a taxpayer-funded reimbursement program while recouping $23,000 from the cost of living there.
According to the Washington Post, she faced the possibility of a House ethics probe for claiming back taxes and monthly bills relating to the entire dwelling rather than for the portion of it that she owned.
A spokesperson for Mace dismissed the Post's reporting, insisting: 'There was no ethics investigation, like at all.'
The Republican recently moved out of the three-bed, $1.6 million pad, a stone's throw from Congress, while she and Bryant try to disentangle their financial affairs and find a buyer.
Bryant, 51, did not respond to requests for comment.
