The US Supreme Court said Tuesday it will review whether President Barack Obama has the authority to protect millions of illegal immigrants from deportation.

The politically charged case -- which comes in an election year -- stems from the administration's appeal of lower court rulings that blocked Obama's efforts to reform immigration policy through executive orders.

More than four million people in the country illegally whose children are legal residents stand to benefit from the president's orders, which would allow them to stay and work in the United States while their legal status is being resolved.

Determined to circumvent Congress, after it failed to pass comprehensive immigration reform, Obama announced the measures in November 2014.

The executive action set off a storm in the US Congress, denounced by Republicans as an abuse of power and tantamount to "amnesty."

Governors of 26 Republican-led states challenged the orders as exceeding the president's executive powers, and federal courts in Texas and Louisiana put them on hold.

The top US court has not scheduled oral arguments in the case, but it is expected to render a decision by mid-June, with the US election season in full swing and less than a month before the Republican and Democratic nominating conventions.

Immigration has dominated the race for the Republican presidential nomination since frontrunner Donald Trump launched his campaign with accusations that Mexico was sending drug dealers and "rapists" to the United States.

The mere fact that the conservative-leaning court has decided to take up the case is seen as a victory for Obama, which argues that immigration policy is the purview of the federal government and that the measures it took do not violate federal law.

"Like millions of families across this country -- immigrants who want to be held accountable, to work on the books, to pay taxes, and to contribute to our society openly and honestly -- we are pleased that the Supreme Court has decided to review the immigration case," said Brandi Hoffine, a White House spokeswoman.

"The policies will make our communities safer. They will make our economy stronger. And they are consistent with the actions taken by presidents of both parties, the laws passed by Congress, and the decisions of the Supreme Court.

"We are confident that the policies will be upheld as lawful," she said.

 Separation of powers

 Texas Attorney General Ken Paxton, however, said the Supreme Court's decision to review the case meant it "recognizes the importance of the separation of powers."

"As federal courts have already ruled three times, there are limits to the president's authority, and those limits enacted by Congress were exceeded when the president unilaterally sought to grant 'lawful presence' to more than four million unauthorized aliens who are in this country unlawfully," Paxton said in a statement.

Among Texas's complaints is the additional cost to the states of issuing driver's licenses to all those given quasi-legal status if the administration's policy is upheld.   

The court decision to review the case was welcomed by Democrats and pro-immigrant lobbying groups, who expressed confidence that the administration's position would be upheld.   

"If Republicans are truly interested in fixing our broken immigration system, they should work with Democrats to pass legislation that would render the president's executive actions unnecessary," said Senate Minority Leader Harry Reid.

Todd Schulte, the president of the tech industry-funded lobbying group FWD.us, called the review "a promising step in the right direction."

Unfreezing the presidential orders would allow "millions of immigrants to come out of the shadows and positively contribute to our economy, and to our communities," he said.

The outcome of the case also could have a bearing on the 2016 elections if it motivates Hispanics, the largest US minority, to go to the polls in November. In 2012, they voted overwhelmingly for Obama.

Even as Trump has made immigrant-bashing a hallmark of his campaign, other Republicans have argued that the party must attract Hispanics to grow.

It's a sometimes thorny issue for Democrats as well.

Under pressure from critics, the government in December stepped up deportations of illegal immigrants with criminal records.

Rights groups and witnesses, however, said raids also targeted immigrants, including families with children, who had arrived from Central America to flee violence in their homeland.

Obama allies -- like Reid and Democratic presidential frontrunner Hillary Clinton -- sharply criticized the raids, insisting the Central American immigrants should have been treated as refugees, not as economic immigrants.