Rep. Colin Allred (D-Tex.), who is trying to unseat Sen. Ted Cruz (R-Tex.) in November, drew harsh criticism from some fellow Democrats this yearfor voting for a Republican-led resolution condemning President Joe Biden’s handling of the U.S.-Mexico border.

Allred’s main opponent in the Democratic Senateprimary said he was “throwing our president under the bus.” Texas’s 2018 Democratic Senate nominee, Beto O’Rourke, said Allred’s vote undercut “our ability to articulate a message that’s effective.”

Allred nonetheless cruised to victory in the March primary, and now he is campaigning on the vote in a vivid display of his efforts to blunt the long-running GOP command of the issue in Texas and elsewhere.

Polls regularly show voters favor Republicans on border security, but Allred has sought to flip the script and lean into an issue that has proven a liability for Democrats in Texas and elsewhere. In the presidential race, Vice President Kamala Harris is working to counteract former president Donald Trump on the issue with a planned trip to the border in Arizona on Friday.

In addition to splitting with Biden, Allred launched early televisionads pitching him as “tough” on the border, hasplayed up family connections in the Rio Grande Valley and made a central issue out of the Senate bipartisan border deal that Cruz and other Republicans blocked earlier this year.

“I think Colin is right on-point,” said state Rep. Eddie Morales Jr., a moderate Democrat who represents a border district. “He’s taken a messaging point from those representatives on the border that actually get to live it day in and day out. It’s refreshing.”

Allred’s border messaging is fueling a competitive challenge to Cruz, who survived a closer-than-expected reelection race against O’Rourke in 2018. This time, Cruz’s seat ranks as one of the Democrats’ most plausible pickup opportunities in the Senate as they largely play defense elsewhere.

On Thursday, the Democratic Senatorial Campaign Committee announced it was making a “multi-million dollar investment” in television advertising in Texas and Florida, another Republican-leaning state.

Cruz has long positioned himself as a border hawk, dating back to when he led opposition to the “Gang of Eight” immigration reform effort nearly a decade ago. He has scoffed at Allred’s messaging, most commonly countering that Allred called former president Donald Trump’s proposal for a border wall “racist” in his first House campaign in 2018.

“Colin Allred is desperately trying to deceive Texas voters about his disastrous open border record,” Cruz said in a statement.

On the campaign trail, Allred talks about spending summers as a young child in Brownsville, where his grandfather was a customs officer. He accuses Cruz and other Republican of treating trips to border communities like a “safari,” parachuting in with rugged-looking clothing fresh off the rack.

“[Cruz] goes down, he points out problems, he talks about what’s happening there — and then he does nothing to help,” Allred said during a recent rally in Austin.

The battle over the border is particularly pitched on the airwaves. A pro-Cruz group is airing an ad where a mother blames Allred’s “policies” for her daughter’s alleged murder by two men in the country illegally. Allred released an ad Thursday where he says Cruz has “been in Washington forever” and “done nothing to secure the border.”

A recent University of Texas poll found that the state’s voters ranked “border security” and “immigration” as the most important problems facing Texas today. The voters said they trusted Trump on those issues more than Harris by a 17-percentage-point margin. Trump’s advantage cut across demographic groups, including the state’s highly-sought-after Hispanic voters.

Allred has kept his distance from Harris since she took over asthe Democratic nominee but spoke last month at the Democratic National Convention on the same night that she did.

Texas Democrats have tried for a retooled message before as the situation on the border has evolved. O’Rourke, who is from El Paso, ran against Cruz in 2018 railing against Trump’s border policies and rhetoric but was critical of Biden’s handling of the issue in his 2022 challenge to Gov. Greg Abbott (R).

Allred has not hesitated to take a page out of the GOP playbook, launching TV ads in July in which he walks along the border wall with law enforcement officials.The imagery has frustrated Cruz.

“He voted against the wall not once, not twice, but three times,” Cruz said in a recent Fox News interview.

Among those votes was one by the Democratic-led House in 2019 to nullify Trump’s attempt to bypass Congress and tap defense funds to pay for a border wall. Allred later said he opposed the funding diversion to “build a wasteful, ineffective wall.”

The fight over the border comes at a time when illegal crossings have dropped in the wake of an executive order that Biden signed in June to severely restrict access to the U.S. asylum system. Encounters between ports of entry have since decreased by more than 50 percent, according to U.S. Customs and Border Protection.

“I know [Republicans] keep talking about the border, border, border,” Rep. Vicente Gonzalez (D-Tex.), who represents a border district, said in an interview. “People vote on how things are going in the moment … and I can tell you it’s been a while since I’ve seen, you know, a resurgence of new migrants coming to the Rio Grande Valley.”

Cruz and his allies have pushed back with a raft of TV ads that highlight how Allred, when he first ran for Congress, called a border wall “racist” and said his generation would “tear it down.” Allred has said he was referring to Trump’s idea of a wall across the entire border.

“What I’ve always opposed is a symbol … being used to pit people against each other,” Allred said in an interview. “To me, having border security means, in places, physical barriers.”

Republicans have also attacked Allred for voting against a 2023 bill that would have made assaulting a law enforcement officer a deportable offense for immigrants. Most Democrats opposed the proposal, arguing it was too broad.

The Senate bill is the biggest border-related issue in the race, though. The proposal would have given the president new authority to effectively shut down the border if daily crossings top 5,000 on average during a given week, among other provisions.

Allred was quick to back it, calling it a “serious opportunity to make real progress.” Cruz joined other Republicans in arguing Biden should take executive action to secure the border and that legislation was not needed.

Allred, speakingat the Austin rally in early September, said Cruz opposed the deal “because he wanted to have the issue to run on in November.”

Cruz argues his objections to the bill were substantive. Among other things, he said in a statement, it would have “normalized 5000 illegal immigrants a day,” referring to the threshold for closing the border.

“This was a terrible bill, which is why I opposed it,” Cruz said.

In the interview, Gonzalez said the deal has given Democrats “a lot of cover” politically but also emphasized the policy “would’ve made a difference.” Gonzalez joined Biden when he traveled to his district to pitch the deal.

The agreement earned the support of the union for Border Patrol agents, the National Border Patrol Council, which nonetheless endorsed Cruz for reelection last month. The union’s vice president, Hector Garza, said in an interview that the endorsement of Cruz was based on a broader track record.

“We know that politicians will change positions as times are changing,” Garza said. “However, something that we’ve always known is that candidates like Sen. Cruz and President Trump have always been supportive of border security measures … and Border Patrol agents.”