The Supreme Court deadlock strikes again, this time in the most-watched immigration case of the year concerning President Obama’s attempt to defer the deportations of an estimated 4 million undocumented immigrants. The 4-4 tie effectively leaves a lower court’s decision, which blocked the implementation of the program, in effect. For immigrants, and their allies and advocates, the result is a bitter stop in the legal journey for Obama’s key executive action.

This afternoon Obama called the Supreme Court’s tie “frustrating to those who seek to grow our economy and bring a rationality to our immigration system,” and “heartbreaking for the millions of immigrants who made their lives here, who raised their children here.”

“I have pushed to the limits of my executive authority,” Obama also said. “We now have to ask Congress to act,” he said, renewing his familiar call to Congress to pass a comprehensive immigration system overhaul, and reiterating that he turned to these deportation deferral programs only after repeated stalling in Congress.

Hillary Clinton, responding to Thursday’s decision, said that Obama “acted well within his constitutional and legal authority in issuing the DAPA and DACA executive actions.” She downplayed the decision as “purely procedural,” and used it as a reminder of “how much damage Senate Republicans are doing by refusing to consider President Obama’s nominee to fill the vacancy on the Supreme Court” left behind by Justice Antonin Scalia’s death in February.

The case concerned whether President Obama had the legal authority to de-prioritize the deportations of a select group of undocumented immigrants. Obama announced the program, Deferred Action for Parents of Americans and Legal Permanent Residents, or as it’s colloquially known, DAPA, in November of 2014. It would have benefited some 4 million people, mainly those who are the parents of US citizen and green card–holding children. The program, President Obama’s second major executive action on immigration, would have also expanded the eligibility requirements for those who could benefit from his first. Obama announced Deferred Action for Childhood Arrivals, or DACA, in 2012, and that program gave similar short-term protection and work authorization to undocumented immigrants who came to the United States as children. That program is still in effect, and some 700,000 undocumented immigrants have enrolled in the program.

Shortly after DAPA was announced, Texas and 25 other states sued the federal government, arguing that Obama did not have the legal authority to implement such a program. The states also challenged the Obama administration on procedural issues, like whether the federal government had given proper notice to states and allowed for comment. In the meantime, the states had requested a preliminary injunction, which the judge granted and the US Court of Appeals for the Fifth Circuit upheld. Thursday’s ruling leaves both DAPA and the expanded DACA blocked.

The case now returns to its original venue, US District Judge Andrew Hanen’s Brownsville, Texas, courtroom. The case has yet to be dealt with on its merits. The National Immigration Legal Center said that immigrant-rights advocates would urge the Department of Justice to immediately seek a rehearing from the Supreme Court.

In the short term, Thursday’s decision is a serious setback for the long-term undocumented immigrants who would have benefited from the programs and who live every day at risk of deportation and separation from their families. President Obama has not only issued key executive actions to benefit undocumented immigrants, he has also deported more than 2 million people during his tenure.

With an estimated 11 million undocumented immigrants in the country, there are still many more millions, however, who do not qualify for either of Obama’s large-scale deportation-deferral programs.