When Kristi Noem takes over her brief as homeland security secretary, she will in some way be responsible for airport sniffer dogs.

This may come as a shock to some, given the South Dakota governor’s hopes of being Donald Trump’s running mate were snuffed out after it emerged she had shot her own puppy.

But it is just one of many ways in which the 52-year-old appears, at least on paper, to be a surprise candidate to oversee the vaunted immigration crackdown that won Mr Trump the White House.

Currently serving her second four-year term in Congress, Ms Noem will soon be responsible for leading a sprawling agency with a $60 billion budget and more than 230,000 employees that oversees everything from US Customs and Border Protection and Immigration to the Federal Emergency Management Agency and the Secret Service.

In her role, she is expected to work closely with Stephen Miller, an anti-immigration zealot who is reported to be Mr Trump’s new deputy chief of staff, and Tom Homan, an unsparing former border force chief who has been installed as a new “immigration tsar”.

In the president-elect’s former administration, Mr Miller played an instrumental role in developing a controversial “Muslim ban” while Mr Homan was the face of the deeply divisive family separation policy.

Ms Noem completes a trio of hardliners tasked with carrying out what Mr Trump has called the “largest deportation operation in American history”, involving the removal of millions of undocumented migrants and a crackdown at the US-Mexico border.

Question marks, however, hang over whether she has the experience to marshall a department that was thrown into turmoil during Mr Trump’s last administration, burning through five different leaders in just four years.

Having dropped out of college aged 22 to run her family ranch, Ms Noem was elected as South Dakota’s first female governor in 2018.

Despite residing more than 1,000 miles from the US-Mexico border, Ms Noem has long sought to keep her state in the national spotlight on the issue of immigration.

She has sent South Dakota National Guard troops to the border and echoed Mr Trump’s harsh rhetoric on illegal immigration, calling the situation at the border an “invasion”.

As governor, she was banned from visiting tribal lands in January this year after claiming that indigenous tribes in her state were benefiting from Mexican drug cartels. Part of her new brief is heading up the department that is involved in tribal issues.

Meanwhile, shortly after Joe Biden took office in 2021, she wrote on X, formerly Twitter: “My message to illegal immigrants… call me when you’re an American.”

She has also voiced support for Greg Abbott, the Texas governor, offering to deliver razor wire for the southern border, and in 2017 expressed her approval of Mr Trump’s “Muslim ban”, describing the nations affected as “terrorist hotbed areas”.

Ahead of the 2024 election, Ms Noem was briefly touted as a potential vice-presidential pick. However, her chances were thwarted after extracts were published from her 2024 biography No Going Back, in which she described killing her family hunting dog Cricket after concluding it was “untrainable”.

Despite defending her actions as the sort of practice permitted on the family farm, the incident provoked horror from many Republicans.

In a separate, since-redacted, passage of her book, she also falsely claimed to have met Kim Jong-un, alleging that the North Korean dictator “underestimated” her, according to The New York Times. Ms Noem has since chalked the farago up to a publishing error.

No stranger to controversy, Ms Noem was sued in March this year after promoting a cosmetic dental surgery in Texas with whom she was alleged to have financial ties.

With his selection of Ms Noem, the president-elect can be assured of one thing: unflinching loyalty.

Since taking office, she has sought to carry favour with Mr Trump and cast herself in his maverick political mould.

She rose to public prominence during the pandemic for refusing to employ a statewide mask mandate and opposing the closure of businesses and churches. She is also a staunch gun rights advocate who once told the National Rifle Association that her two-year-old grandchild has multiple guns.

Her loyalty has at times taken a more sycophantic tone. In 2020, she presented Mr Trump with a 4ft replica of Mount Rushmore with his face carved alongside the pantheon of great American presidents, according to The New York Times.

Ahead of the 2024 election, Ms Noem was one of the earliest governors to endorse Mr Trump ahead of his 2024 run for president.

The president-elect, in turn, has called Noem a “terrific person”. If not for the unfortunate dog incident, she may well have been destined for even higher office.

Still, she has remained one of the president-elect’s arch defenders, with The Atlantic reporting that Ms Noem participated in strategy briefings about the state of the race.

Delivering an address to the Republican National Convention earlier this year, she heaped praise on the president-elect, claiming he had been “unjustly prosecuted” in his legal travails and had in fact “honoured the constitution” – in contrast, she said, to Mr Biden.

Political aside, Ms Noem may be best known to many for hosting a campaign rally in Philadelphia which descended into an impromptu disco.

Two Trump supporters required medical attention at the event, when they fainted in the heat.

Mr Trump then spent half an hour standing on stage and occasionally dancing to music, with Ms Noem occasionally joining in.