Doug Fiefia has been elected the first US state senator of Tongan descent.

The Republican swapped a state House of Representatives seat after two years in office to claim Utah's 18th district.

The social conservative, who carved out a slice of US history for the Pacific diaspora, called his campaign "very grassroots".

"I took on an incumbent that had been in office for 14 years, and so it was nerve wracking," he told Radio New Zealand.

"The institutional money didn't come."

But despite attracting strong fundraising from the Polynesian community, Mr Fiefia could well court controversy over his anti-immigration stance.

Mr Fiefia's Tongan-born parents moved onto Utah during the 1970s.

But he conceded that in 2026, Tongan nationals have been stopped at the US border.

Tonga is under a near-total travel ban since January.

Eligibility for tourist, businesses, student and exchange visitor visas are all but impossible coming with the cost of a $US20,000 bond.

The Kingdom has been impacted alongside numerous African and Middle Eastern nations amid a broad travel crackdown.

Tongans have a high rate of 6.45 percent of its citizens overstaying their visas, nearly three times the rate of an average foreign visitor to the US.

Mr Fiefia believed the data does not lie.

"I think it was probably something that we needed to take a little bit more seriously before they were actually put on that list," he said.

"It started important conversations, that if a country gives you a visa and they say it's for a certain time, we need to respect that."

Reflecting on President Donald Trump's wider crackdown on immigrants to the US, Mr Fiefia did not feel as though the Tongan-American community have been affected.

"The videos that we see online of ICE that go viral, I don't see much of that happening within the state of Utah," he said.

Utah has one of the largest and most established Tongan populations throughout the US among the deeply Christian state that included nearly half of Tongans belonging to the Church of Latter-day Saints.

Mr Fiefia described the political backlash against the Republican party in the midterm elections as a "bloodbath" result nationwide.

He called the Polynesian community a "mixed bag" politically, though while maintaining strong conservative leanings.

But the 37-year-old admitted that, overwhelmingly, they are not better off in the last two years under Republican leadership.

"People voted with their pocketbooks and what their account said at the end of the day," Mr Fiefia said, "that ultimately, we've failed to make things more affordable for Americans and Utahns."