The US Supreme Court on Thursday blocked President Barack Obama's plan to spare millions of illegal immigrants in the country from deportation in a split ruling that the president said was "heartbreaking" for those affected.
The 4-4 ruling, coming seven months before Obama's term in office ends, marked the latest success that his Republican adversaries have had in thwarting a major policy initiative of the Democrat president.
Obama had hoped that overhauling the US immigration system and resolving the fate of the estimated 11 million people in the country illegally would be part of his presidential legacy.
A split ruling was possible because the court was down to eight justices, four liberals and four conservatives, after conservative justice Antonin Scalia died in February.
The Republican-led Senate has refused to act on Obama's nomination of appeals court judge Merrick Garland to replace Scalia.
The decision leaves in legal limbo the roughly 4 million people Obama's action was meant to help.
The plan was tailored to let those people - who have lived illegally in the United States at least since 2010, have no criminal record and have children who are US citizens or lawful permanent residents - get into a program that shields them from deportation and supplies work permits.
In an appearance at the White House after the ruling, Obama expressed frustration at the court's inability to issue a decisive ruling on the merits of the case and at Senate Republicans for "willfully" keeping the court shorthanded.
"The fact that the Supreme Court wasn't able to issue a decision today doesn't just set the system back further — it takes us further from the country that we aspire to be," he said.
"I think it is heartbreaking for the millions of immigrants who made their lives here, who raise families here and hope for the opportunity to work, pay taxes, serve in our military and more fully contribute to this country we all love in an open way."
Obama also said that the voters will play a critical role in deciding how the country moves forward on this issue.
The president also tweeted: "Our immigration system is broken, and we need Congress for a long-term solution."
— Barack Obama (@BarackObama) June 23, 2016
Obama's fellow Democrats also were quick to express dismay.
"Yet another example of SCOTUS not being able to function as final word on a crucial constitutional issue," tweeted Senator Patrick Leahy, chiding Republican colleagues for blocking the appointment of a new justice.
"Do your job," he demanded.
— Sen. Patrick Leahy (@SenatorLeahy) June 23, 2016
Congressman Xavier Becerra declared: "As a nation built by immigrants, America must fight to keep families together, not tear them apart."
— Xavier Becerra (@RepBecerra) June 23, 2016
A victory for Republicans
Republicans, however, celebrated what they saw as a victory for efforts to stop Obama exceeding his executive authority to bypass Congress and force through controversial measures.
The nation's top elected Republican, US House of Representatives Speaker Paul Ryan, and others in his party welcomed the ruling.
"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," said Texas Attorney General Ken Paxton, a Republican.
"Obama's illegal action on immigration has been blocked! A huge win for our Constitution and for our rule of law," tweeted Congressman Tom Marino, echoing the views of many of his colleagues.
— Rep. Tom Marino (@RepTomMarino) June 23, 2016
The ruling is likely to further amplify the role that the immigration issue will play in the run-up to the Nov 8 presidential election in which voters will pick Obama's successor.
Republican White House hopeful Donald Trump has adopted some of the most hardline anti-immigrant rhetoric ever used by a major party candidate, vowing to build a wall along the Mexican border. He tweeted his approval of the block on President Obama's immigration plan.
SC has kept us safe from exec amnesty--for now. But Hillary has pledged to expand it, taking jobs from Hispanic & African-American workers.
— Donald J. Trump (@realDonaldTrump) June 23, 2016
He has also vowed to suspend all immigration by Muslims and people "from areas of the world where there is a proven history of terrorism against the United States, Europe or our allies."
Trump's Democrat rival, Hillary Clinton, has by contrast vowed "to create a pathway to citizenship, keep families together, and enable millions of workers to come out of the shadows.
President Obama had unveiled his plan in November 2014.
It was quickly challenged in court by Republican-governed Texas and 25 other states that argued that Obama overstepped the powers granted to him by the US Constitution by infringing upon the authority of Congress.
His unilateral executive action bypassed the Republican-led Congress.
The Supreme court appeared divided along ideological lines during oral arguments on April 18, with liberals indicating support for the administration and conservatives opposed.
Because the court was split, a 2015 lower-court ruling invalidating Obama's plan was left in place. The plan never was implemented because the lower courts had blocked it.