The young immigrants at the center of Congress’s current negotiations just received some shocking news — from a federal court in California.

Judge William Alsup of the Northern District of California ordered the Trump administration on Tuesday night to (partially) resurrect the Deferred Action for Childhood Arrivals program, which protects nearly 700,000 unauthorized immigrants from deportation and allows them to work in the US legally, a program the federal government is in the process of winding down.

But it’s still unclear whether this is good news for the immigrants who have DACA, or just another layer of confusion and uncertainty.

The order (the result of a lawsuit filed by the University of California) directs the Trump administration to make it possible for people who have or have had DACA to apply for renewals again — something that many of them were prevented from doing when the administration announced an end to the program on September 5, 2017, while others missed a narrow window for one final renewal last fall.

Tuesday night’s order doesn’t necessarily mean that the estimated 22,000 people who have already lost DACA protections since September or are set to lose them by March 5 — or the several hundred people a day who are set to lose work permits starting March 5 — can mail renewal applications and stop worrying about their futures.

There are very big questions about how quickly US Citizenship and Immigration Services will move to implement the order — and how long the order will remain in effect before being stopped or overturned in a higher court.

Even the immigration advocates who are litigating the lawsuit are stressing the fragility of Tuesday night’s decision, and arguing it shouldn’t take any pressure off Congress to pass a bill that would create some sort of permanent protection (or even full legal status, including the ultimate ability to apply for citizenship) for DACA recipients and those who will be eligible when they turn 15.

The question is whether Congress will agree that this ruling — which looks like a game changer at first glance — doesn’t actually give them an out.

Tuesday night’s order directs the Trump administration to set up a process to start accepting DACA renewals again

Alsup’s ruling isn’t a decision about whether the Trump administration acted illegally or unconstitutionally to end DACA in September 2017. It’s a preliminary injunction — an order to temporarily stop a government policy, while the courts hash out the question of whether the policy is legal and constitutional. That makes it, by its nature, temporary.

Preliminary injunctions are issued when the judge believes it’s likely that the policy in question will ultimately be struck down in court — and when the cost of allowing the policy to go into effect is large and irreversible enough that it’s best not to risk it.

In this case, of course, the policy already has gone into effect (despite the tendency of the Trump administration and others to say that DACA “expires” on March 5).

In September, the Department of Homeland Security stopped allowing people to apply for an initial two-year grant of protection from deportation and work permit under DACA. It prevented people whose current work permits expired after March 5, 2018, from applying for renewal.

The department set a deadline of October 5 for anyone whose work permit was going to expire in the next six months to apply for one last renewal — a deadline that roughly 22,000 DACA recipients missed. (Many, it turns out, because of Postal Service delays and/or narrow deadline interpretations by US Citizenship and Immigration Services.)

Judge Alsup’s order doesn’t fully reanimate the DACA program. It does not allow people who had not previously applied for DACA — even if they became eligible (say, by turning 15) after the Trump administration stopped accepting new applications on September 5 — to apply. It doesn’t allow those who currently have DACA to apply for “advance parole,” or the ability to leave the United States and come back.

The order says the Trump administration has to make it possible for people who already were approved for DACA to apply for two-year renewals of their work permits and deportation protections.

That applies to the estimated 11,000 people whose work permits have already expired since September. It also applies to immigrants whose work permits are set to expire in the coming weeks or months but who didn’t get a chance to reapply under the administration’s rules.

This doesn’t mean DACA recipients are home free if they just reapply now

Tuesday night’s order doesn’t say that the Trump administration has to start accepting DACA renewal applications again immediately.

US Citizenship and Immigration Services, the agency that administered DACA, has to provide public notice about how people can apply for renewals again — and it has to do so in a “reasonable” amount of time. That’s not a specific timeline; it just means that if the plaintiffs think USCIS is dragging its feet, they can go back to Judge Alsup and argue that the government is violating the order by not being “reasonable.”

It’s not at all clear how long it might take USCIS to do that. It’s only just finished assessing the scope of the Postal Service errors that resulted in more than 1,900 applications getting rejected as “late,” six weeks after the problem was brought to light.

It’s also not clear how long Alsup’s ruling will stand. The government has the ability to appeal it to the Ninth Circuit Court of Appeals, and from there to the Supreme Court. Or it can ask the Ninth Circuit to put a hold (a “stay”) on the injunction. The government’s odds of getting a hold are decent — especially because the Supreme Court has already slapped down one order by Alsup in this case (an attempt to force the government to turn over documents about its decision-making process for ending DACA).

That puts people who might be eligible to reapply for DACA now in a bind. Do they submit renewal applications — including a $495 check — as quickly as possible, in hopes that USCIS will start accepting them even before it puts out formal guidance? Or do they wait, so they don’t accidentally violate rules for renewal that USCIS hasn’t yet set? And what happens if they send in their renewal applications but another court overturns Alsup’s order before they’ve heard back?

It’s an extremely difficult risk calculus — the sort that requires guidance from an immigration lawyer to suss out. But even immigration lawyers are telling their clients, and the public, different things.

The office of California Attorney General Xavier Becerra said that “our understanding is that the administration must grant renewal status to DACA grantees.” But Marielena Hincapie of the National Immigration Law Center said that because “there isn’t yet a mechanism” for US Citizenship and Immigration Services to accept those renewals, DACA recipients “can’t go back and renew today.”

The upshot for the people who might be affected by Tuesday night’s injunction is that it replaces the certainty that their DACA will end with a very fragile possibility that they can renew it.

Judge Alsup ruled that the Trump administration needed to show its work better before ending a program that people relied on

Legally, Judge Alsup found, there’s reason to believe that the decision to end DACA was made so hastily that it could violate the Administrative Procedure Act, which governs the actions of federal agencies.

Ironically, the legal argument against DACA was largely based on the claim that President Obama violated the APA by creating the program. But as far as Alsup is concerned, that’s not relevant to the question of whether Trump violated the APA in ending it.

For one thing, Alsup writes, “the agency’s decision to rescind DACA was based on a flawed legal premise.” The administration said it was ending the program because DACA was unconstitutional — if Republican state officials followed through with a threat to sue over DACA’s constitutionality, the administration didn’t think it could win.

“Our collective wisdom,” Attorney General Jeff Sessions said in September, “is that the policy is vulnerable to the same legal and constitutional challenges that the courts recognized” when the Fifth Circuit Court of Appeals stopped an attempted expansion of the DACA program, and a related deferred action program, from going into effect in 2015.

Because the Trump administration acted preemptively to kill DACA, the courts never actually hashed out the question of DACA’s constitutionality. Alsup found the administration made a false assumption that DACA wouldn’t be constitutional.

“One way an agency action can be deemed arbitrary” under the law, said Josh Rosenthal of the National Immigration Law Center (who is litigating a similar case over DACA in New York), “is if the legal premise is erroneous.” Alsup’s injunction finds that might have happened here.

That finding opens the door for the Trump administration to actually hash out the constitutionality of DACA in court — and if it ultimately persuades the courts that the program was unconstitutional, it would be able to proceed with killing it. The second argument Alsup makes, according to Rosenthal, would be harder for the Trump administration to respond to.

“It’s established law,” says Rosenthal, “that if people have built reliance around a government policy” — even if that policy isn’t formalized as a regulation, as DACA wasn’t — “the agency has to take into account before changing the policy.” Even if the agency thinks the policy is illegal, it has to consider that “reliance interest.”

Ever since DACA went into effect in 2012, critics of the program from left and right have argued that it was by design a temporary stopgap that could be reversed by a future administration; but in practice, advocates argued, DACA recipients (not to mention their employers, families, schools, etc.) had been able to rely on the security the program offered them for five years.

The “reliance interest” doesn’t require the administration to keep doing something illegal — it just requires the administration to consider that impact. And Judge Alsup wrote on Tuesday that it’s probable the Trump administration didn’t consider it enough.

Ultimately, Rosenthal says, a loss on “reliance interest” grounds could force a government agency to go back to square one and redo the decision-making process. The question, of course, is what the decision-making process to end DACA actually was — and whether the government wouldn’t just come to the same conclusion even if it had taken “reliance” into consideration.

DACA is still very fragile

The injunction ordering the government to partially resurrect DACA comes in the midst of plodding negotiations in Congress over a permanent replacement for the program. Those negotiations were kick-started when the administration announced it would bring DACA to a close — and they’ve proceeded with an eye toward the March 5 “deadline.”

But Alsup’s ruling could send a signal to some in Congress that the March 5 deadline isn’t as much a problem as they’d feared, since people whose work permits are set to expire on March 6 should now (pending USCIS instructions) be able to renew them.

That’s an outcome that the advocates who just won a victory with Alsup’s injunction clearly dread. “The uncertainty illustrates why there’s still an urgency for Congress to act,” Rosenthal said.

Ironically, the arguments made by DACA advocates now are strikingly similar to arguments made by critics of the program when it was in effect. They’re saying that an executive branch program, one that can be started up or shut down at any time with the stroke of a judge’s pen, shouldn’t be a substitute for legislation: something that is permanent both in the law and for the people who benefit from it.

While DACA was in effect, even people who thought it usurped the authority of Congress weren’t agitating for Congress to act to protect DREAMers. The pressure wasn’t on until DACA was brought to an end.

And with so many obstacles to a congressional DACA deal already, it’s still not clear whether Judge Alsup’s fragile, partial, likely short-lived ruling will be taken by Congress as a permanent reprieve.