Julián Castro wasn’t a part of the Democratic presidential debate on June 27, but for a short moment that night, his influence took center stage.

After fielding question after question from a panel of moderators, 10 Democrats in Miami — sans the two Texans in the race — were asked to raise their hands if they supported the repeal of a law that criminalized unauthorized border crossings.

Nine candidates seemed to raise their hands. Nearly a dozen candidates now appear to be on board.

That night, the candidates were essentially endorsing an idea first raised in the campaign by Castro. The repeal of that part of U.S. immigration law, Section 1325, had in many ways become his signature issue. The topic was brought up again a month later during a debate in Detroit, and after seeing many of his opponents embrace it, his campaign triumphantly proclaimed in an email blast to supporters that Castro’s “policy leadership dominated the discussion.”

“I had just caught that part of the debate, and when I heard 1325 mentioned I thought, mira, mira, look at how quickly that’s catching on,” said Democratic state Rep. Poncho Nevárez of Eagle Pass, one of Castro’s early supporters.

But while other candidates have built strong support behind policy ideas that are popular among the primary electorate — such as U.S. Sen. Bernie Sanders with his Medicare-for-all spiel or U.S. Sen. Elizabeth Warren’s detailed plans on a number of issues — Castro’s proposal hasn’t elevated his candidacy to the next level. Since entering the race in January, Castro has languished near the bottom of most national polls, hovering around 1% or 2%.

That’s despite being the only Latino in the race and the first Democratic candidate to unveil a comprehensive immigration plan, which, in addition to the repeal of Section 1325, called for policies that are commonplace among Democratic candidates, like reversing President Donald Trump’s travel ban and providing a pathway to citizenship for people in the country illegally.

Some political strategists say that Castro’s proposal has helped his campaign, and his advocacy for it helped play a role in getting him qualified for the September debate.

But it remains unclear, they say, how far it will carry him.

“The field right now is just so crowded, but I think if he can stomach through and grit through, then he can get traction,” said Lillian Salerno, a podcast host and Democrat who previously ran for Congress in Texas. “He’s the pace car on immigration.”

Pushing the party left

People who cross the U.S.-Mexico border without authorization can be prosecuted under 8 U.S.C. Section 1325 of the federal immigration code, which deals with illegal entry, or 8 U.S.C. Section 1326, which deals with illegal reentry. Castro wants to axe Section 1325, which has been on the books for decades, and instead treat the violations as civil offenses — which could still lead to defendants being deported and barred from reentering the country, according to Cristobal Ramón, senior policy analyst with the Immigration Project at the Bipartisan Policy Center.

Castro’s campaign said there should be an administrative process for levying penalties against individuals who cross the U.S.-Mexico border without authorization, but it hasn’t said what that process would entail. A spokesman for his campaign told The Texas Tribune that, if elected, Castro would repeal Section 1325 and “put all undocumented immigrants — as long as they have not committed a serious crime — on a pathway to citizenship.”

“The civil process, including legal penalties and adjudication under the law, would be retained for new migrants,” said Sawyer Hackett, the spokesman. “We would work with our allies to dramatically improve conditions in Central America with a 21st century Marshall Plan to ensure there aren’t hundreds of thousands of migrants fleeing their home countries to seek refuge in the U.S.”

Castro’s proposal comes as Trump’s immigration policies have outraged Democrats — in part, due to his administration’s “zero tolerance” directive in 2018. But aggressive criminal prosecutions of migrants who enter illegally began in 2005 under President George W. Bush. Ramón said there was no incentive for the next two administrations to halt Bush’s directive, known as Operation Streamline, which instructed U.S. Customs and Border Protections to refer people to the Department of Justice for criminal prosecutions under these two provisions.

Presidential administrations have the discretion to criminally prosecute using either provision of U.S. immigration code. Obama used Operation Streamline the same way Bush did; the Trump administration, meanwhile, prosecuted all adults irrespective of any mitigating circumstances, leading to a high number of family separations.

Castro’s policy stance has prompted calls from Republicans that any Democrat who supports Section 1325’s repeal is pulling the party to the left. The proposal has been denounced by a number of Republicans, who have called it a policy of “open borders” and argued that it will hurt Democrats in the general election.

“Julián Castro is pushing a radical agenda that prioritizes illegal immigrants over Americans,” said Trump Victory Committee spokeswoman Samantha Cotten. “Texans will reject Castro’s call for open borders and free health care for illegal immigrants.”

But Castro has avoided entertaining criticism that repealing Section 1325 will lead to open borders, something he has dismissed as a “right-wing talking point.”

Still, even some Democrats have professed skepticism about the idea. During the Miami debate, home state tensions flared between Castro and Beto O’Rourke after the latter expressed unease with what the repeal of the law would mean for prosecuting criminals like drug smugglers and human traffickers. Castro then accused the fellow Texan of not having “done his homework” on the issue of immigration.

A month later in Detroit, Castro tussled with former Vice President Joe Biden on the same subject.

“I found that Julián, excuse me, the secretary, we sat together in many meetings,” Biden said. “I never heard him talk about any of this when he was the [housing] secretary.”

“If you cross the border illegally, you should be able to be sent back,” Biden added. “It's a crime. It's a crime.”

Castro responded, “Mr. Vice President, it looks like one of us has learned the lessons of the past. One of us hasn’t. What we need are politicians who have some guts on this issue.”

“I have guts enough to say his plan doesn’t make sense,” Biden said curtly.

But many Democrats — from presidential candidates to some members of the Texas delegation — have endorsed it. Some, like Warren, have gone so far as to compliment Castro for first bringing the issue to light. During an MSNBC appearance in May, Warren said that she’s “very interested” in Castro’s work and thought he had some “really good ideas around” immigration policy.

“There’s always a delicate dance people do where they want to admit when someone’s right but don’t want to give them too much credit because it takes away from their own standing,” said state Rep. Diego Bernal, D-San Antonio, another early supporter of Castro.

“For the most part,” he said, “there was a silent admission that [Castro] had thought more about immigration reform than the rest of them had and they were now examining their own place on the issue — or deciding that he was right.”

Finding his place

Castro was once seen as a more moderate Democrat, especially while working under Obama’s leadership. But his immigration policy exemplifies what many see as a leftward shift during his presidential bid.

“Across the board, this Democratic primary field has lurched pretty severely to the left on almost every topic,” said Colin Strother, a Texas Democratic strategist who once advised both Joaquin and Julián Castro. “I think some of the most liberal takes on immigration and immigration reform just go hand in hand with the leftward movement we’re seeing from this field.”

“I think what Julián is trying to do is force us to have a broader conversation about, ‘What kind of country are we?’” Strother said. “Forget open borders — do we still have open doors to people that are coming here seeking a better life?”

Since revealing his immigration platform, Castro has tried to position himself as one of the leading voices on the issues — and one of the more liberal voices at that. But while Castro’s position on Section 1325 has shifted the debate on immigration, it hasn’t moved the needle much on his own campaign.

He achieved a brief bump in the polls after his back-and-forth with O’Rourke in the debates and later boasted on Twitter that nearly 16,000 people, 71% of whom were new donors, contributed to his campaign in the day after his onstage appearance in Miami. But he’s mostly languished around 1% or 2% in national polls — enough for him to qualify for the next round of debates, but leaving him at or near the bottom among candidates who will make that stage.

One key problem, experts say, is that many voters still simply don’t know who Castro is.

“His platform to run from is that he was a former HUD secretary. Can you name any other former HUD secretaries? It’s just not a very high-profile position,” said a longtime national Democratic operative who asked to remain anonymous because he has friends working on Castro’s campaign.

“Even if he’s leading on issues, people have to know who you are before they start listening to you about issues. And I think he has a huge problem with that.”

Still, after qualifying for the third Democratic debate in Houston next month, he now has another chance to shine — or at least a chance to try to prove to voters he’s best equipped to stand up to the president, who is pushing a border wall along the U.S.-Mexico border and has separated thousands of migrant families at the border.

“When it comes down to nut-cutting time, he’s going to make it,” Nevárez, the Eagle Pass Democrat, said. “I just have this unshakeable doubt that with issues like this, he’s going to be able to cut and clarify right to the end.

“He’s going to be part of the cream that rises to the top.”