Texas Attorney General Ken Paxton has defeated Senator John Cornyn in the Republican runoff primary, a stunning upset that may give Democrats an opening in the Senate battle.

Paxton, 62, won the primary despite being outspent by a 9-to-1 margin, and will now face Democratic state legislator James Talarico in the November general election. The outcome of that race will help determine whether Democrats can win back control of the US Senate.

Texas Senate Race

The Senate primary was the most expensive in US history, with Paxton and Cornyn spending millions of dollars on their campaigns. Paxton’s victory marks a significant defeat for an incumbent who served in Congress for 23 years, including 12 years as a high-ranking member of the Senate Republican leadership team.

Paxton’s win may be seen as a victory for President Donald Trump’s populist base in Texas, who campaigned against Cornyn as too old and out-of-touch with conservatives. Trump endorsed Paxton last week, congratulating him on his victory and saying he would “become a fantastic, common sense senator”.

Implications and Reactions

Many Democrats view Paxton as the weaker candidate and see an opportunity to flip a Senate seat in a state that hasn’t elected a Democrat to the Senate since 1988. Polls indicate a tight race, with some analysts predicting that the outcome could be decided by a small margin.

The outcome of the Texas Senate race will have significant implications for the balance of power in the US Senate, and could potentially give Democrats the opportunity to pass key legislation and block Republican efforts to advance their agenda.