A three-judge appeals court panel appeared to be divided again as it heard arguments on Wednesday over the merits of a Texas immigration law that has become a major flashpoint between the Biden administration and Governor Abbott.

In a case that challenges court precedent holding that immigration enforcement is exclusively the federal government’s domain, Texas went first, arguing that the Biden administration’s lack of immigration enforcement has left the state to fend for itself in handling influxes of millions of illegal immigrants and cartel-supplied drugs.

The lack of federal enforcement has put Texas in “dangerous and unchartered territory,” Texas’s solicitor general, Aaron Nielson, said in arguments before the Fifth Circuit Court of Appeals at New Orleans. 

“I don’t think anybody disagrees that there is an unprecedented border crisis,” he said, referencing both the volume of crossings and the sophistication of the cartels.

“There’s always been people who crossed the border. But before we talked about hundreds of thousands, now we talk about millions,” Mr. Nielson said. “The cartels have essentially got this down to a science. There’s a logistical supply chain, and they move people through the supply chain, where they make a great deal of profit for themselves.”

Despite the crisis, when Texas has sought help from the federal government, the answer it has received again and again is “we don’t have enough resources,” Mr. Nielson said. Instead of following Texas’s lead with its Senate Bill 4, which offers additional resources to help protect the border, he added, the federal government has been hostile at every turn.

“They’re not just saying no,” Mr. Nielson said in response to a question from Chief Judge Priscilla Richman. “Respectfully, they’re destroying our Texas property. They’re suggesting awful things about Texas at the United States Supreme Court, which are demonstrably untrue. And they’re suing us.” 

He said Texas had looked at Supreme Court precedent and tried to develop legislation in line with it, but acknowledged that “maybe Texas went too far.” 

In response to a series of prodding questions from Chief Judge Richman — both on Wednesday and in previous oral arguments — Mr. Nielson also clarified some aspects about how SB 4 would work in practice. For one, he said, if Texas delivered a migrant to a port of entry and the federal government ordered him back to Texas, then the state likely couldn’t rearrest. 

“I have some disadvantage because no Texas court has yet interpreted SB 4,” he said, adding that from the attorney general’s perspective, the federal government’s dictate would block the state from rearresting. 

“It’s not a secret that if federal law allowed Texas to go further, Texas would go further,” he said. “But that is the line that Texas perceives in federal law and that is as far as it goes.”

In the case of an illegal immigrant entering Texas from another state, such as Arizona, “that person would not be covered. Because they did not directly enter Texas from a foreign nation.” 

The Biden administration fired back that the state was attempting to “rewrite Texas SB 4 from the podium.”

Daniel Tenny, who is representing the U.S. government, referred frequently to the appellate court’s stay opinion issued last week when it kept SB 4 temporarily blocked. 

“For nearly 150 years, the Supreme Court has held that the power to control immigration — the entry, admission, and removal of noncitizens — is exclusively a federal power,” Chief Judge Richman wrote for the majority in that analysis, adding that the Supreme Court’s Arizona v. United States ruling “provides considerable guidance.” 

Mr. Tenny maintained that entry and removal of citizens is exclusively a federal power and added that Texas’s law creates foreign affairs concerns. 

An appointee of President Trump who dissented from last week’s order blocking SB 4 from going into effect, Judge Andrew Oldham, further pushed back against the Biden administration in Wednesday’s arguments. 

“As far as I can tell, never in the history of the nation has the United States achieved what they have achieved in this case, which is a facial invalidation of a statute that never went into effect with no cause of action,” he said. “And in order to preserve it, you have to show me that every single application of every single provision is unconstitutional in every single way.”

Judge Oldham pressed the federal government about why it was pushing to ban outright every provision of the Texas law before it was allowed to go into effect and play out. 

“Everyone in the courtroom agrees that Arizona is your best case, including me,” he said to Mr. Tenny, noting that the Arizona ruling was much narrower.

“Why is it that you want to so radically extend the Arizona rationale in this case?” Judge Oldham asked, to which Mr. Tenny replied that the state laws regulating entry and removal intrude “on an area that the federal government has authority over in the immigration space.”

“Is there anything that a state can do to regulate entry and removal, anything at all?” Judge Oldham asked. Mr. Tenny insisted states “can’t exercise their own independent regulatory authority” but can cooperate with the federal government on some enforcement measures. 

When it came to the government’s foreign affairs concerns, Judge Oldham also asked if Texas merely arresting and returning a migrant to a port of entry would be problematic for the federal government.

The Biden administration’s lawyer said Mexico has expressed concerns about its nationals being arrested even if they aren’t deported, and added that the Arizona ruling is “instructive” in this area. 

“Arizona did not involve any effort by a state to remove somebody from the United States, but the foreign affairs concerns were front and center in that opinion,” he said. “The court emphasized that, of course, there’s concerns about reciprocal treatment of U.S. citizens abroad, and taking a noncitizen and, based on their immigration status, putting them in prison is a serious matter and can indeed be a foreign affairs matter.”

It is not clear when the three-judge panel will issue its ruling, but Texas has indicated it will appeal the case to the Supreme Court if the state loses.