DALLAS (AP) — Republican Sen. Ted Cruz and Democratic Rep. Colin Allred met for their only debate Tuesday night, trading attacks over abortion and immigration in a closely watched race that could help determine which party wins control of the U.S. Senate.

Nationally, Democrats view Texas as one of their few potential pickup chances in the Senate this year, while Cruz has urged Republicans to take Texas seriously amid signs that the former 2016 presidential contender is in another competitive race to keep his seat.

From start to finish in the hourlong debate, Cruz sought to link Allred to Vice President Kamala Harris at nearly every opportunity and painted the three-term Dallas congressman as out of step in a state where voters have not elected a Democrat to a statewide office in 30 years.

Allred, who would become Texas' first Black senator if elected, hammered Cruz over the state's abortion ban that is one of the most restrictive in the nation and does not allow exceptions in cases of rape or incest. The issue is central to Allred's underdog campaign and his supporters include Texas women who had serious pregnancy complications after the state's ban took effect.

Pressed on whether he supports Texas' law, Cruz said the specifics of abortion law have been and should be decided by the Texas Legislature.

"I don't serve in the state Legislature. I'm not the governor," he said.

Cruz later blasted Allred over his support of transgender rights and immigration polices of President Joe Biden and Harris, accusing him of shifting his views on border security from the positions he took when he was first elected to Congress in 2018.

"What I always said is that we have to make sure that as we're talking about border security, that we don't fall into demonizing," Allred said.

Allred accused the two-term U.S. senator of mischaracterizing his record and repeatedly jabbed Cruz for his family vacation to Mexico during a deadly winter storm in 2021 that crippled the state's power grid.

The two candidates closed the debate by attacking each other, with Cruz painting an Allred victory as a threat to Republicans' grip on Texas.

"Congressman Allred and Kamala Harris are both running on the same radical agenda," Cruz said.

Allred, meanwhile, cast himself as a moderate and accused Cruz of engaging in what he described as "anger-tainment, where you just leave people upset and you podcast about it and you write a book about it and you make some money on it, but you're not actually there when people need you."

The last time Cruz was on the ballot in 2018, he only narrowly won reelection over challenger Beto O'Rourke.

The debate offered Allred, a former NFL linebacker, a chance to boost his name identification to a broad Texas audience. Allred has made protecting abortion rights a centerpiece of his campaign and has been sharply critical of the state's abortion ban. The issue has been a winning one for Democrats, even in red states like Kentucky and Kansas, ever since the U.S. Supreme Court's decision in 2022 to strip away constitutional protections for abortion.

Cruz, who fast made a name for himself in the Senate as an uncompromising conservative, has refashioned his campaign to focus on his legislative record.

Allred has meanwhile sought to flash moderate credentials and has the endorsement of former Republican U.S. Reps. Adam Kinzinger and Liz Cheney.

The two candidates alone have raised close to $100 million, according to the most recent reports from the Federal Election Commission. Tens of millions more dollars have been spent by outside groups, making it one of the most expensive races in the country.

Despite Texas' reputation as a deep-red state and the Democrats' 30-year statewide drought, the party has grown increasingly optimistic in recent years that they can win here.

Since former President Barack Obama lost Texas by more than 15 percentage points in 2012, the margins have steadily declined. Former President Donald Trump won by 9 percentage points in 2016, and four years later, won by less than 6. That was the narrowest victory for a Republican presidential candidate in Texas since 1996.

"Texas is a red state," said Mark Jones, a political science professor at Rice University in Houston. "But it's not a ruby-red state."