Hundreds of protesters rallied outside the Supreme Court in Washington while lawyers presented arguments for and against ending the federal DACA program on Tuesday.

The Supreme Court heard over an hour and a half of oral arguments that will decide the fate of 700,000 young undocumented migrants under temporary protection from deportation in the Deferred Action for Childhood Arrivals (DACA) program.

According to an NBC account of Tuesday’s arguments, the judges weighed two crucial points: whether the courts had jurisdiction to rule on the government’s shut down of the DACA program, and whether the federal government gave sufficient explanation for terminating the program.

Ted Olson, who defended the DACA program before the court, argued federal law required the government to give sufficient explanation before ending a program that affects hundreds of thousands of people.

It would be one thing, he said, “if they provided a rational explanation and took responsibility for their decision.” But, he argued, the government simply ended the program by declaring it illegal without giving any explanation.

According to NBC, the liberal judges seemed to side with Olson while four conservative justices: Clarence Thomas, Neil Gorsuch, Samuel Alito, and Brett Kavanaugh seemed to agree with the Justice Department’s argument that the courts had no jurisdiction to rule on the government’s decision to end a federal program. That leaves Chief Justice John Roberts to possibly be the deciding swing vote.

What is DACA?

The Obama administration created the DACA program in 2012 to provide work permits, Social Security numbers, and protection from deportation for young undocumented migrants who came to the country as children, many of whom “have no memory of any home other than the United States,” as per the Associated Press.

Trump, who has expressed support for the program in the past, is fighting to end the program in an effort to further dismantle Obama-era legislation and continue his crackdown against immigration. The Trump administration terminated the program in 2017 after initially allowing it to continue.

“Many of the people in DACA, no longer very young, are far from ‘angels.’ Some are very tough, hardened criminals,” Trump tweeted falsely early on Tuesday, as the program bars felons and others convicted of serious crimes.

Trump insinuated that he plans to use DACA recipients as political leverage if the Supreme Court reverses the decision: “President Obama said he had no legal right to sign order, but would anyway. If Supreme Court remedies with overturn, a deal will be made with Dems for them to stay!”

The Trump administration was also expected to argue to the court that overturning DACA will discourage migrant flows. Critics, like former Obama White House chief of staff Denis McDonough, counter that “the program has no clear magnet effect for those migrating today,” because it is reserved for migrants who arrived more than 12 years ago.

DACA supporters point to evidence like a recently released longitudinal national study from Harvard which found dramatic improvements in the quality of life of the program’s beneficiaries.

The cost of DACA deportations could run as high as $7.5 billion, diverting resources from the record number of migrant children in detention and other urgent border crises. Additionally, hundreds of DACA recipients currently serve in the Military Accessions Vital to National Interest (MAVNI) program, where immigrants with language skills and cultural knowledge are of vital importance in certain Special Forces missions.

The Supreme Court’s DACA hearing comes the same day as hundreds of emails sent by Trump immigration policy architect Stephen Miller were revealed by the Southern Poverty Law Center. The emails, which were sent to Breitbart in 2015 and 2016, demonstrate the extreme white nationalist views undergirding the Trump administration’s immigration crackdown.

The Supreme Court is expected to rule on the DACA case some time in the Spring of 2020.