WASHINGTON -- The Supreme Court couldn't reach a majority for or against President Barack Obama's plan to defer deportation for millions Thursday, effectively leaving his executive actions on hold and undocumented immigrants in limbo.

In a one-sentence ruling, the justices simply said, "The judgment is affirmed by an equally divided court." But they didn't indicate how they voted -- a sign that the court was sharply at odds along ideological lines.

The split decision means a lower court ruling that effectively blocked the program will stand, and no national precedent will be set as to whether the president acted within the law when he announced it in November 2014.

Obama expressed disappointment at the Supreme Court's "inability to reach a decision" and stressed that its failure to decide was also partly to blame on Senate Republicans' unwillingness to consider the person he chose to fill the seat of the late Justice Antonin Scalia.

"This is part of the consequence of a Republican failure so far to give a fair hearing to Merrick Garland, my nominee to the Supreme Court," Obama said at a White House briefing, adding that their recalcitrance is "not a sustainable strategy" and that it stalls progress on issues that need definite answers.

On that note, Obama made clear that the ruling is only nominal and doesn't carry any legal weight -- let alone stand for a value judgment on his presidency.

"If we have a full court issuing a full opinion on anything, then we take it seriously," he said. "This we have to abide by, but it wasn't any kind of value statement or a decision on the merits on these issues."

Perhaps because of its limited reach, Ken Paxton, the Texas attorney general, offered muted praise for the Supreme Court's move.

"Today’s decision keeps in place what we have maintained from the very start: one person, even a president, cannot unilaterally change the law," he said in a statement. "This is a major setback to President Obama’s attempts to expand executive power, and a victory for those who believe in the separation of powers and the rule of law.”

The case, United States v. Texas, stood to test the limits of executive power in the face of congressional inaction on immigration -- a chance for Obama to prove that he, like his predecessors, had the authority to help millions of undocumented immigrants who want to live here without fear of deportation.

On that issue, the justices had sent an ominous sign to the president when they first agreed to hear the case, asking the Obama administration and the 26 states challenging it to explain whether the deportation relief plan violated the Constitution.

No lower court had previously addressed that question, leading to the speculation that a conservative majority on the Supreme Court had every intention of turning the dispute into a constitutional showdown -- perhaps to send a message to Obama about the separation of powers in his last year in office.

But Scalia's unexpected death in February changed the landscape, and a diminished court had to hear the case just as the political branches were facing off over the confirmation of who would replace him on the bench.

That may explain why the justices largely skirted the constitutional issue at oral arguments, focusing instead on more technical legal matters, such as the meaning of "lawful presence" in immigration law and the doctrine of standing -- or Texas' ability to claim injury and sue over a policy area where Congress has given the executive branch broad latitude.

Obama relied on that latitude when he announced the centerpiece of his ambitious immigration plan, Deferred Action for Parents of Americans and Lawful Permanent Residents -- or DAPA -- which promised to grant a reprieve of deportation and work authorization to parents of U.S. citizens and others who are lawfully in the country.

But before the program could get off the ground, a coalition of states, led by Texas, sued the federal government in a small courthouse near the U.S.-Mexico border -- a move that legal observers viewed as an attempt to land the lawsuit before a sympathetic judge who might rule against the administration.

U.S. District Judge Andrew Hanen, the George W. Bush appointee who was assigned the case, turned out to be precisely that and then some: He not only issued a nationwide injunction that put the brakes on Obama's plan, but has also ruled sweepingly against the administration on issues of ethics that have left the Department of Justice and thousands of undocumented immigrants on edge.

House Speaker Paul Ryan (R-Wis.) seemed to ascribe more value to the ruling than it's worth -- calling it a vindication of Congress' power to legislate.

“Today, Article I of the Constitutio n was vindicated," he said in a statement. "The Supreme Court’s ruling makes the president’s executive action on immigration null and void. The Constitutio n is clear: The president is not permitted to write laws — only Congress is. This is another major victory in our fight to restore the separation of powers.”

The House of Representatives and a group of three immigrant mothers were also part of the case -- each taking sides in the controversy over how Obama's immigration policy affects their interests.

Without a definitive ruling either way, the Supreme Court left no doubt that the stakes of the presidential election -- and the fight over the court's future composition -- are higher than ever.

This detail wasn't lost on Obama.

"Now we've got a choice about what we're going to be as a country, what we're going to teach our kids, how we're going to be represented in Congress and the White House," he said.

Elise Foley contributed reporting. This article has been updated with remarks from Obama.