In the most consequential 4-4 deadlock of the term, the Supreme Court has all but killed President Obama’s most significant attempted reform of immigration policy — which would have allowed up to 4.5 million immigrants to apply for protection from deportation and work legally in the US.

The Court announced Thursday that it was unable to reach a decision in the case United States v. Texas. That means the ruling of the Fifth Circuit Court of Appeals stands — which had kept the programs (known as DAPA and DACA+) from going into effect.

Unlike other cases on which the Court's deadlocked since the death of Justice Antonin Scalia in February, this one can’t simply be taken up again once the ninth seat is filled — Obama will no longer be in office.

The Court’s deadlock could lead to judicial chaos close to the election: Pro-immigration advocates have challenged a circuit court’s authority to make decisions affecting the whole country, and have hinted they’ll bring a suit in another region of the country to put the executive actions into effect there.

In the medium term, the future of immigration policy will be decided by the winner of the 2016 presidential election: Presumptive Republican nominee Donald Trump has promised to get rid of the existing program offering protections to young unauthorized immigrants, while presumptive Democratic nominee Hillary Clinton has promised to find a way to expand protections even further than Obama did (which means she’d have to use a different justification than the one offered in the now-abortive Obama programs).

But the Court’s deadlock means that President Obama will be able to take credit only for the 700,000 immigrants protected from deportation through the 2012 program — and for the more than 2 million immigrants deported over his eight years in office. For a president who came into the White House promising to bring unauthorized immigrants out of the shadows, he’ll leave it having made it simply more dangerous for them to be there.

The Supreme Court kept a red light on efforts to help up to 4.5 million immigrants

In November 2014, President Obama issued a series of memos declaring executive actions on immigration. Two of those are at issue in this case.

One memo expanded the existing Deferred Action for Childhood Arrivals program, or DACA, which since 2012 had allowed immigrants who'd come to the US as children to apply for temporary protection from deportation and work permits.

The other memo added a new deferred action program — the Deferred Action for Parents of Americans program — which would have allowed millions of unauthorized immigrants who have US citizen or permanent resident children to apply for deportation protection and work permits as well.

The two 2014 actions are usually referred to as DAPA/DACA+. Since the states won in the lower courts, both programs have been put on hold since the first ruling was issued in February 2015. The original DACA program from 2012, however, wasn’t challenged in the states’ suit. (To prevent confusion, I'll just refer to DAPA instead of DAPA/DACA+ when talking about the 2014 actions.)

A group of 23 states — all but three of them under unified Republican control — filed a lawsuit shortly after the programs were announced to keep them from going into effect; they were joined by four Republican governors (three of whom have Democratic attorneys general who wouldn't let the state officially join the case) and one Republican attorney general.

In February 2015 — just a few days before the government was scheduled to start accepting applications for expanded DACA — Judge Andrew Hanen of the Southern District of Texas issued an injunction, preventing the government from moving ahead with the program on the logic that the states were "likely" to prevail on some of their claims. The Fifth Circuit Court of Appeals upheld the injunction. And in January, the Supreme Court agreed to hear the case.

The deadlock means the eight justices couldn't agree on the basis of the case

As the case has made its way through the courts, it's gotten much broader. Initially, the injunction was based on a narrow claim that the Obama administration hadn't used the right procedure in instituting DAPA. The Fifth Circuit ruled that DAPA was also (or at least was likely to be) illegal on the merits. And the Supreme Court decided to consider a constitutional issue: whether DAPA violates the "take care" clause of the Constitution.

That offered the Supreme Court justices several different ways to make up a five-vote majority — and almost as many ways to deadlock.

If the Court had gotten five justices to agree that the states didn’t even have standing to bring the case, for example, it could have overturned the Fifth Circuit's ruling and let DAPA and DACA+ go forward — even if there was disagreement about the underlying legality.

On the other hand, if five justices had been able to agree that the states did have standing and that the Obama administration's actions were illegal for any reason — even if there wasn't a consensus on the other arguments against them — they would have been able to affirmatively uphold the states’ argument.

The 4-4 deadlock is a sign that neither happened: The court’s liberal justices couldn't get the conservatives to agree that the states didn’t have standing and the program was legal; the conservatives couldn’t get the liberals to agree on the legitimacy of the lawsuit and the illegality of the programs.

Because the Supreme Court didn’t rule, advocates may try to get a second opinion in another circuit

Even though the Supreme Court has heard arguments in United States v. Texas, the case hasn’t actually been resolved. Technically, the only rulings have been preliminary ones — the underlying ruling on the case itself hasn’t even been issued by the lowest court judge. With the Supreme Court’s punt, the Fifth Circuit’s injunction is upheld — and the case will continue to plod, zombielike, through the courts until it receives a final ruling.

Meanwhile, supporters of the president's executive actions may try to get a different coalition of states to sue in another court to start implementing them — creating a possible split between appellate courts, in which the executive actions are ruled constitutional in parts of the US and unconstitutional in other parts. The logic behind this is that the Fifth Circuit doesn’t get to set law for the entire country just because the Supreme Court is deadlocked. But it would create judicial chaos.

It would also be extremely difficult to do quickly — and if President Trump is elected in November, the whole issue will be moot. Advocates might simply deem DAPA and DACA dead and acknowledge that the 4.5 million immigrants it could have protected will remain vulnerable to deportation for the remainder of Obama's time in office. Their only hope would be for a Democratic president to be inaugurated in 2017 and try some other way to grant relief to unauthorized immigrants.

Obama’s legacy: closer to "deporter in chief" than immigrant champion

Federal immigration enforcement has totally transformed over the past 20 years, and deportations have escalated accordingly — from 183,000 in 1999 to a high of 400,000 during the first several years of the Obama administration.

President Obama has spent most of his time in office trying to impose some sort of control on all of this — to make sure the government is choosing who's most important to deport, rather than arbitrarily deporting anyone Immigration and Customs Enforcement agents get their hands on. His first attempts — setting high and low "priorities" for deportation and telling immigration agents to follow them — were something both sides in the current court case agree he could do but that rank-and-file immigration agents frequently ignored in favor of their own judgment.

But near the end of his first term, Obama appeared to have found a tool that worked: allowing people to proactively apply for protection from deportation. He created the first deferred action program, DACA, in 2012; it's been solidly effective.

After comprehensive immigration reform stalled in Congress in 2013, pressure grew on Obama to use the tool that had worked — deferred action — to protect other groups of low-priority immigrants, and he did just that with DAPA and expanded DACA in 2014. But the Supreme Court has just undone that attempt, resetting Obama’s immigration legacy to where it was at the end of his first term.

Over the past few years, the administration has quietly and quickly curbed deportations. They’re now closer to where they were 10 years ago. But the fact remains that Obama will leave office having deported far more immigrants than he protected — and having left those immigrants who are still in the US vulnerable to the next president’s whims.

What does the ruling mean for people in the real world?

In theory, very little changes. DAPA and DACA+ hadn’t gone into effect because of the court case; now they will never go into effect (at least in their current forms).

Due to an alarmingly broad order from the original judge in the Texas lawsuit, there’s a possibility that 100,000 immigrants who got their work permits renewed under DACA in 2014-’15 might end up publicly doxxed. That’s understandably terrifying to the immigrants in question. But it is ultimately unlikely.

The real effect here is opportunity cost. An estimated 4.5 million immigrants had been waiting on the Supreme Court’s decision to find out whether they’d be able to seek protection from deportation and work legally in the US, and the Supreme Court has just told them they can’t.

The evidence from DACA, which has protected about 700,000 immigrants for the past three and a half years, indicates this is a very real loss. Three-quarters of DACA recipients had been able to get better-paying jobs, 30 percent had gone back to school, and 59 percent said they could help support their families. There's evidence that DACA helps keep immigrants integrated into American life — instead of losing interest in school or career because they feel their immigration status holds them back.

Those are opportunities that their older counterparts will never be able to get through DACA+, and that millions of parents of people like them will never be able to get through DAPA.

This ruling could create problems for a President Clinton

Even the existing deferred action program, DACA, is subject to the whims of the president. Donald Trump has already promised to do just that in his first few days in office.

Some pundits have argued that this means the real immigration fight is what happens in November, rather than what happened in the courts this spring. Insofar as the next president will choose whether to end deferred action, that's true. But the Supreme Court’s inability to find a five-vote majority supporting DAPA and DACA+ might shape what options a president has to expand it, as Hillary Clinton has promised to do.

Clinton has said she wouldn't deport immigrants who hadn't committed crimes but hasn't explained how she'd protect them. Because Clinton has explicitly promised to protect immigrants that the Obama administration decided it legally could not protect (including the parents of DACA recipients), she would either need to expand DAPA or find another way to offer immigrants similar protections.

Given that the Supreme Court can’t agree that even President Obama’s DAPA proposal was legal, that could be a very difficult needle to thread. But a President Clinton will be under even more pressure than her predecessor to find a way to protect immigrants. That could create trouble.

The racist history of US immigration policy