Senator Ted Cruz of Texas fended off an aggressive and well-funded Democratic challenger to win a third term and preserve decades of Republican Party dominance in the nation’s most populous red state, according to The Associated Press.

“Keep Texas, Texas,” had been the refrain of Mr. Cruz’s campaign. In keeping his seat, he dashed what had been rising hopes among some Democrats that years of demographic changes and urbanization, along with aggressive turnout efforts, could start to flip the state.

“Tonight the people of Texas have spoken, and their message rings clear as a bell across our great state: Texas will remain in Texas,” Mr. Cruz said in a speech declaring victory to a crowd of cheering hundreds in a downtown Houston hotel ballroom.

He highlighted gains with Hispanic voters in the traditionally Democratic areas in the Rio Grande Valley: “We are seeing generational change in South Texas,” he said.

The victory helped ensure that Republicans would be able to take control of the U.S. Senate next year.

Mr. Cruz congratulated his opponent, Representative Colin Allred, a Democrat from the Dallas area who earned his seat in 2018 during a wave of Democratic enthusiasm that nearly ousted Mr. Cruz in his last re-election fight.

Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.

Thank you for your patience while we verify access.

Already a subscriber? Log in.

Want all of The Times? Subscribe.