AUSTIN—Texas Republican Sen. John Cornyn, a heavy favorite and by far the bigger spender in his race, defeated Democratic long-shot candidate Rick Noriega to secure a second term Tuesday night.

Cornyn had 54 percent of the vote to Noriega’s 43 percent with about three-fourths of precincts reporting. Libertarian Yvonne Schick was a distant third.

“It’s a humbling experience to go before 24 million Texans for a job interview. No matter where you live, no matter who you are, no matter your situation in life, we’re going to represent you,” Cornyn said at his election party.

With his victory, Cornyn heads back to a U.S. Senate ruled by the opposing party. Democrats expanded their control of the Senate by capturing GOP-held seats in North Carolina, New Hampshire and elsewhere.

“I like a good fight,” Cornyn said. “You can disagree with people and argue with people on policies and still treat people with dignity and respect, but I think that a lot of it depends on the majority, how they wield their power.”

Cornyn won most of the vote in West Texas and East Texas, while Noriega fared well in predominantly Hispanic parts of the state in South Texas and along the Texas-Mexico border, according to Associated Press exit polling. The two roughly split the votes in Houston, Dallas-Fort Worth and south Central Texas.

“We fell a little short, but there’s certainly no shame