Supporters of Talarico went berserk as TVs at a watch party in Austin, the state’s capitol, projected him the winner.

They hugged, they kissed, and they drank to a reality that many say they dared not believe would come true.

Emerging on stage to rapturous applause at his official watch party at a nearby performing arts theatre, Talarico pronounced: “We just took back Texas.”

“We just proved that all the money in the world is no match for the people of Texas,” he continued, referring to his win over Paxton whose campaign was backed by Elon Musk, the world’s richest man.

He invoked religious themes that have grown familiar to his campaign, comparing his unlikely odds to the biblical story of David and Goliath.

“This win, this win is for every Texan who’s ever wondered if anyone is listening,” he said. “I hear you, we hear you. And tonight the world hears you.”

For decades, the idea of a Democrat winning a statewide race had felt like a pipe dream for Texas liberals.

As the nation’s second most populous state, Texas has been a bastion of conservatism, routinely rolling out Republican policies that are later employed elsewhere.

But throughout the campaign, polls suggested state legislator Talarico was breaking through with voters, energising a Texas Democratic base desperate for new leadership.

Spending in the race skyrocketed, and it quickly grew to become the most expensive US Senate race in history, with more than half a billion dollars spent.

Billionaire Elon Musk poured in $158m (£117m) to a super PAC supporting Paxton’s campaign – a point that Talarico used in attacks on Paxton’s campaign.

Then two members of the Bush family, the Republican political dynasty that counts Texas as its political launchpad, backed Talarico in a stunning move foreshadowing Paxton’s doom.

George Washington University political science professor Quardricos Driskell told the BBC that Paxton was a major part of Republicans’ downfall, calling him an “objectively terrible candidate”.

He said the win in Texas by Talarico, combined with another upset on Tuesday that ousted the state’s Republican governor Greg Abbott, was “absolutely historic”. Abbott’s loss marked the first time a Democrat had won a race for governor in the state since the 1990s.

“This wasn’t just a tsunami, not just a referendum, but this was a bloodbath,” Driskell said about Democrats gains in the Lone Star State. “A clear distinction that the country wants to go in a different direction”.

Talarico defeated a well-known opponent, Dallas Congresswoman Jasmine Crockett, in the Democratic primary. Then continued to maintain good polling numbers despite an onslaught of negative adverts, including attacks on past comments where he supported transgender people.

Throughout his campaign, he frequently leaned into his religious upbringing – as the grandson of a Southern Baptist preacher who spent time in a seminary – sprinkling his stump speeches with biblical references.