In a 2016 court filing, Marco Rubio, then a senator running for president, made the case that the Constitution conferred citizenship on essentially all children born in the United States. His argument was a crisp rendition of what was until recently the consensus understanding.
But the views he expressed are now in tension with an executive order issued by President Trump in January that seeks to restrict birthright citizenship. The Supreme Court seems likely to hear a direct challenge to the order’s constitutionality in the term that starts in October.
The little-noticed court filing helps show how quickly the Republican Party and parts of the mainstream of conservative legal thought have shifted on the issue. It is also a reminder that the question of who is born a citizen may affect eligibility to be president.
Tommy Pigott, a State Department spokesman, said in a statement that “it’s absurd the NYT is even wasting time digging around for decade-old made-up stories,” adding that Mr. Rubio was “100 percent aligned with President Trump’s agenda.”
Mr. Pigott’s statement did not address the arguments in the 2016 brief or how to square them with the executive order.
Peter J. Spiro, a law professor at Temple University and an expert on citizenship, said in an email that the 2016 filing was a “powerful, succinct statement of why the 14th Amendment has been interpreted to cover almost all children born in the United States, regardless of parental immigration status.”
“There’s no reason why the argument he put to work in 2016 couldn’t be put to work today against the Trump executive order,” Professor Spiro wrote.
Mr. Rubio, now the secretary of state, submitted the brief in response to a lawsuit filed in federal court in Arkansas by a fringe presidential candidate, David Librace. Mr. Librace’s suit contended that Mr. Rubio was ineligible to be president because he was not, as the Constitution requires, a “natural born citizen.” Mr. Rubio was born in 1971 to Cuban immigrants who would not become citizens until 1975.
Judge Brian S. Miller of the Federal District Court in Little Rock dismissed the suit. “Although the questions raised by Mr. Librace are interesting, they are questions that he simply does not have standing to bring,” the judge wrote, noting that “courts have consistently held that voters do not have standing to sue based on the ‘birther’ argument.”
The arguments Mr. Rubio made in his brief were broader than they needed to be to win his case. He addressed, for instance, not only the Constitution’s presidential eligibility clause but also the provision of the 14th Amendment on birthright citizenship.
He went on to say that the amendment, the common law on which it was based and the leading Supreme Court precedent all confirmed that “persons born in the United States to foreign parents (who were not diplomats or hostile, occupying enemies) were citizens of the United States by virtue of their birth.”
Mr. Trump contends, by contrast, that the children of parents in the United States unlawfully or temporarily are not automatically citizens because they are not, as the 14th amendment requires, “subject to the jurisdiction” of the United States.
The gap between the two positions would not have mattered in Mr. Rubio’s circumstances. His parents were lawful residents when he was born, meaning he would have been on the right side of the line Mr. Trump has sought to draw, including in an executive order he issued on his first day in office seeking to curtail birthright citizenship for many children. The order has been tied up in the courts ever since.
On the other hand, those distinctions make no sense, Professor Spiro said.
“Particularly weak is the administration’s attempt to distinguish among legally present noncitizens,” he said. “By trying to exclude the children of so-called nonimmigrants — including student visa holders and temporary workers — the administration loses the argument that it’s only targeting those who are here in violation of the law.”
Mr. Rubio’s brief certainly did not draw that line. Instead, he defended birthright citizenship wholesale, saying that the 14th amendment was “intended to remove any doubt that all persons born in the United States, regardless of race, ancestry, previous servitude, etc., were citizens of the United States.”
The Supreme Court issued a decision in June arising from the executive order, but the justices did not address the directive’s constitutionality. Since then, several lower courts have ruled against the order, accepting arguments along the lines of those offered by Mr. Rubio.
In July, for instance, the U.S. Court of Appeals for the Ninth Circuit upheld a preliminary injunction blocking the executive order, on grounds nearly identical to those sketched out in 2016 by Mr. Rubio, who is a defendant in the case. Among his official responsibilities are issuing passports and overseeing immigration laws abroad.
In a filing this month, the administration vowed to move quickly “to enable the Supreme Court to settle the lawfulness of the citizenship order” in the term that will start in October. The filing added that the solicitor general, the administration’s top appellate lawyer, “has not yet determined which case or combination of cases to take to the court.”
Mr. Rubio’s brief was filed in response to a lawsuit that at least bordered on the frivolous, during a grueling and heated presidential campaign. He may have paid little attention to the contours of the arguments made on his behalf. Such a brief was not, in any event, the place to make a major or even a particularly considered statement on birthright citizenship.
The general assertions in Mr. Rubio’s 2016 brief were wide-ranging and confident, reflecting the conventional wisdom. In the coming months, the nation is likely to learn whether the consensus holds.