James Talarico has defeated Republican Ken Paxton to become the first Democrat to win a US Senate seat in Texas since 1988, helping his party secure control of both chambers of Congress.

The result breaks decades of Republican dominance in America’s second most populous state. It came alongside the defeat of Republican governor Greg Abbott on Tuesday, giving Democrats their first victory in a Texas governor’s race since the 1990s.

Talarico, a former schoolteacher and state legislator little known until last year, centred his campaign on rising living costs under Republican leadership. Paxton argued that his opponent was too progressive for Texas, while Donald Trump campaigned alongside the Republican on several occasions.

Money did not settle the contest. Spending exceeded half a billion dollars, making it the most expensive US Senate race in history. Elon Musk contributed $158m (£117m) to a super PAC supporting Paxton, funding that Talarico repeatedly used against his opponent. Two members of the Republican Bush family backed the Democrat.

“We just took back Texas,” Talarico told cheering supporters at his official election-night gathering in an Austin performing arts theatre. Elsewhere in the capital, supporters hugged, kissed and celebrated as television coverage projected his victory.

The grandson of a Southern Baptist preacher, who himself spent time in a seminary, Talarico frequently used biblical references and compared his campaign’s odds to David and Goliath. He defeated Dallas congresswoman Jasmine Crockett in the Democratic primary and maintained strong polling despite negative adverts, including attacks on his past support for transgender people.

Paxton brought considerable political liabilities. His own party impeached him in 2023 over corruption accusations, although the state Senate acquitted him. A separate fraud case brought by the US Securities and Exchange Commission was dismissed.

Quardricos Driskell, a political science professor at George Washington University, called Paxton an “objectively terrible candidate” and described the combined Democratic victories as “absolutely historic”. His assessment places weight on the candidate as well as the wider political climate.

Voters frustrated by consumer prices, including petrol, largely blamed Trump’s tariffs and the Iran war. Immigration presented a different tension: falling border crossings had been popular, but polls since late summer suggested most Hispanic Texans disapproved of Trump and favoured Democrats by a significant margin.

Hispanic people comprise a third of Texas’s population. Many interviewed before the election, including voters who had switched to Trump in 2024, cited immigration enforcement that detained citizens and indiscriminately rounded up non-violent offenders. Those accounts help explain the backlash, though they do not establish how much each issue contributed to the result.