A courtoom sketch of Judge Leonie M. Brinkema. (William J. Hennessy Jr.)

When a federal judge in Alexandria issued a preliminary injunction Monday night against President Trump’s travel ban, she limited her ruling to the state of Virginia. But Judge Leonie M. Brinkema’s opinion could have much broader implications for the fight against the ban.

Brinkema was the first judge in the country to actually confront the legality of the executive order barring travel from seven majority-Muslim countries.

While a temporary restraining order out of Washington state put the ban on hold nationwide, the judge who issued that ruling did not delve deeply into the facts of the case. The 9th Circuit Court of Appeals said much in its decision about Trump’s motives and the separation of powers. But, ultimately, that panel ruled on narrow due process grounds. Its opinion did not even mention the statute on which the executive order is based, which gives the president broad power over immigration and national security.

Brinkema addresses that statute, as well as the record of Trump’s comments and the case law to justify their inclusion.

“Judge Brinkema spells out a lot more; she really fleshes out one of the possible claims, and that’s the religious discrimination claim,” said David Martin, a professor at the University of Virginia who, for many years, helped shape immigration policy inside the government. “That may well prove to be the strongest or more fruitful line of inquiry for the plaintiffs in these various cases, particularly if they’re trying to reach past green-card holders or people on immigrant visas. It’s hard to get there without a religious discrimination case of some kind.”

(Peter Stevenson/The Washington Post)

Green-card holders and people with long-term immigrant visas have certain rights that visitors, students and others do not. But if the executive order is deemed unconstitutional on religious discrimination grounds, those distinctions are irrelevant.

While one federal judge’s decision is not binding on any other court, experts agreed that Brinkema’s thoroughness will probably make her opinion persuasive to other districts.

“It was a very well-reasoned, thoughtful decision. Frankly, I think, a more careful decision than the 9th Circuit decision,” said Steve Legomsky, former chief counsel for immigration services in the Department of Homeland Security. In her opinion, Legomsky said, Brinkema “ pretty methodically went through the various statements by Trump. . . . They put great weight on the opinions of the former national security officials to show the absence of counterevidence from the Trump administration. For both of those reasons, I think the Virginia opinion is very important.”

Brinkema also brings to the case extensive national security experience. She presided over the trial of Sept. 11, 2001, conspirator Zacarias Moussaoui, among other high-profile cases.

“It was a thoughtful opinion, it’s well considered, it wasn’t hastily done like some of these other decisions had to be in light of circumstances,” said Justin Cox of the National Immigration Law Center. His group is involved in several lawsuits against the ban, including one filed in Maryland last week focused on refugees. That case is specifically focused on religious discrimination.

“Legally [the Virginia ruling] is actually quite significant because it’s the first court to squarely hold that the executive order violates the establishment clause,” Cox said.

The danger for opponents of the ban is that, should the Justice Department appeal Brinkema’s decision, they will face the more conservative 4th Circuit rather than the left-leaning 9th Circuit.

“It would be a close call,” Legomsky said. “There is such strong evidence of religious discrimination — it’s really hard to know.”