AP
Barack Obama.
And that could happen right in the heat of a campaign season in which immigration reform has featured prominently and inflamed political tensions unlike any other issue.
The Justice Department said Tuesday it would appeal to the high court a decision handed down Monday night by the 5th Circuit Court of Appeals in Louisiana, which upheld a lower court's block on the implementation of the plans.
"The Department of Justice remains committed to taking steps that will resolve the immigration litigation as quickly as possible in order to allow DHS to bring greater accountability to our immigration system by prioritizing the removal of the worst offenders, not people who have long ties to the United States and who are raising American children," Patrick Rodenbush, a spokesman for the Department of Justice, said in a statement.
"The Department disagrees with the Fifth Circuit's adverse ruling and intends to seek further review from the Supreme Court of the United States."
The decision from the 5th Circuit court, which had been expected, nevertheless served as a blow for proponents of Obama's executive actions, which he announced nearly one year ago and had planned to begin implementing in May.
The plan would shield about 5 million immigrants living in the country unlawfully from deportation. It would extend the protection of immigrants who came to the country as children without documentation, as well as parents of US citizens and legal permanent residents.
"The Supreme Court has been clear that presidents have the authority to set federal immigration policy, and I'm confident that the President's actions will ultimately be upheld," said Sen. Dick Durbin (D-Illinois), the No. 2 Senate Democrat.
The big question is when that will happen. The Justice Department can appeal quickly to the Supreme Court, at which point the state of Texas - which led a field of 25 states in suing the administration over the plans - would have 30 days to respond.
The Supreme Court must decide by mid-January to hear the case in the ongoing term that ends next June. If it decides in February or later to hear the case, it could push a decision to 2017 - likely after Obama has left office.
Judge Carolyn Dineen King, who was the sole dissenter in the three-judge panel, criticized her colleagues for a nearly five-months-long review that preceded the eventual decision.
"There is no justification for that delay," she wrote in her opinion.
If further legal proceedings move swiftly, it would mean that - for the second straight election - one of the president's signature legislative achievements would make its way to the nation's highest court just months before the nation is set to choose a president.
In 2012, the Supreme Court heard a case that could have dismantled the Affordable Care Act. Ultimately, the court upheld the law's key provision - a mandate that most people buy health insurance or pay a penalty - handing Obama a significant victory on his way to re-election.
This time, Obama is not on the ballot. But Hillary Clinton, the Democratic presidential front-runner, has promised to go even further than the current president in taking executive action to reform the immigration system in the face of congressional opposition.
Most Republican presidential contenders, meanwhile, have pledged to undo Obama's executive actions if they are elected to the nation's highest office. Republican presidential front-runner Donald Trump, for one, has gone much further, promising to deport the approximately 11 million immigrants living in the country unlawfully and to build a wall along the US-Mexico border.