The U.S. Supreme Court is hearing Monday arguments in a landmark case -- the United States v Texas -- debating the legality of President Barack Obama’s executive actions on immigration.
Who is affected: Roughly 4 million undocumented immigrants who are living in the United States.
What does the court case involve:
The case focuses on Obama's 2014 program known as Deferred Action for Parents of Americans (DAPA). The program defers deportation for undocumented immigrants who have been in the U.S. since at least 2010, have a child who is a U.S. citizen or is in the country legally, and do not have a criminal record.
Obama said he took executive action because Congress had failed to overhaul the immigration system.
Who is behind the lawsuit: Texas is leading 26 states as well as congressional Republicans in challenging Obama's executive actions. They argue Obama doesn't have the power to effectively change immigration law.
Possible court outcomes:
Side with administration: About 4 million people would be allowed to live and work in the U.S. temporarily without constant fear of deportation.
Side with the states: The lower court rulings, which have frozen the immigration actions, would likely stand through the remaining months of Obama's presidency.
Tie 4-4: A tie is possible after the death of Justice Antonin Scalia in February, which left eight members on the court. A tie would let the lower court rulings stand.
Sidestep immigration issue: The high court also could decide that Texas and the other states don't have the right to sue in federal court, a procedural outcome that would largely sidestep the divisive immigration issue.
Decision expected: The court is expected to decide by late June.
Arguing the case:
Administration is represented by its top appellate lawyer, Solicitor General Donald Verrilli Jr., who has argued many high-profile cases before the court, including the Affordable Care Act, the constitutionality of same-sex marriage and the Defense of Marriage Act.
The states are led by Texas’ solicitor general, Scott Keller, who has argued before the court regarding Texas' right to reject a proposal for license plates featuring a Confederate battle flag as well as in defense of Texas’ sharp restrictions on abortion clinics.
Where the 2016 presidential candidates stand:
Republicans: Candidates Donald Trump, Ted Cruz and John Kasich have said they would immediately reverse any actions allowed to take place.
Democrats: Hillary Clinton and Bernie Sanders have said they would expand upon those efforts.
Some material for this report came from AP.
