The Supreme Court will hear oral arguments Monday in a blockbuster case that threatens to kill the executive actions President Obama took in 2014 to save nearly 5 million illegal immigrants from deportation.

It’s possible the eight-justice bench could deadlock in deciding whether the president overstepped his executive authority. The court has shown signs that it’s struggling to reach consensus without a ninth member since the unexpected death of Justice Antonin Scalia.

A 4-4 tie would still be a win for Texas and the 25 other states challenging a pair of executive actions –– which created the Deferred Action for Parents of Americans (DAPA) initiative and expanded the Deferred Action for Childhood Arrivals (DACA) programs –– that a lower court put on hold in February 2015.

Here are six things to know ahead of Monday’s oral arguments.

1.  Before the Supreme Court can rule on the merits of the case, it must first decide if Texas had a legitimate basis to bring the case forward to begin with.

The states argue they will have to spend more in public services like healthcare, law enforcement and education if undocumented parents of both American citizens and legal permanent residents are allowed to stay in the country.

Texas says it would be most burdened by having to issue a substantial number of new driver’s licenses, a benefit that is partly subsidized. The administration argues those costs are self-generated.

“Texas has chosen to subsidize driver’s licenses for all aliens within various federal immigration categories,” the administration said in a brief. “If that choice no longer suits Texas’s interests, it can make a different choice.”

If the court finds the states lacked standing, the case would be dismissed without consideration of the other challenges being lobbed and Obama would be free to launch his programs.

2. House Republicans will have 15 of the 90 minutes reserved for arguments to fight for the president’s programs to be struck down.

The Supreme Court issued the order giving lawmakers a chance to be heard after the House, in an unprecedented move, filed an amicus brief in support of the states.

The resolution allowing House Speaker Paul RyanPaul Ryan6 things to know about the Supreme Court immigration case SNL’s Paul Ryan insists he’s not running for president Ryan sticks neck out on Puerto Rico debt relief bill MORE (R-Wisc.) to file the brief passed largely along party lines.

“The executive is certainly free to disagree with the immigration laws and to try to persuade Congress to revise them. And the executive even has some discretion (albeit nowhere near the unlimited discretion it claims) to decide how best to use its limited enforcement resources. But the executive does not have the power to authorize—let alone facilitate—the prospective violation of the immigration laws on a massive class-wide scale,” the House said in its brief.

Democrats who disagreed have filed their own brief in support of the administration.

Erin Murphy, an attorney with the D.C. law firm Bancroft PLLC, will argue on behalf of the House.

3. One of the questions the Supreme Court is being asked to decide is whether President Obama should have followed the notice-and-comment requirements of the Administrative Procedures Act.

The administration argues that its actions serve as guidance for the Department of Homeland Security in establishing national immigration enforcement policies and priorities but do not change the way the law operates – therefore not triggering the notice-and-comment requirements under APA.

If the court agrees with the states’ arguments that DAPA represents one of the largest changes in immigration policy in the nation’s history and required public notice and an opportunity to comment, Democrats say the programs are as good as dead.

“The trial said you had to use the APA to take a discretionary action,” Rep. Zoe Lofgren (D-Calif.) said. “If the Supreme Court says that, no future president will be able to act.

4. Court watchers say either Justice Anthony Kennedy or Chief Justice John Roberts could swing to the left in this case and side with the administration.

In Arizona v. United States in 2012, both Kennedy and Roberts joined the court’s liberal members in a 5-3 ruling – Elena Kagan recused herself – that struck down parts of an Arizona state law that made it a crime to be in the state without legal papers, apply for or get a job in the state and allowed police to arrest immigrants they suspect could be deported.

“A principal feature of the removal system is the broad discretion exercised by immigration officials,” Kennedy wrote in the court’s decision, on which Roberts joined with the court’s liberal justices Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor. “Federal officials, as an initial matter, must decide whether it makes sense to pursue removal at all.”

In addition to this ruling, immigration advocates have pointed to Roberts’s history of having a narrow view of standing as a sign he might rule against the states.

5. The court’s decision will also have enormous implications for President Obama’s domestic policy legacy. In both 2008 and 2012, Obama campaigned heavily on promises to push for comprehensive immigration reform, including a pathway to citizenship for millions of undocumented immigrants. The platform energized Latino voters, who flocked to Obama by overwhelming margins in both elections.

Seven years later, however, Obama has yet to make good on his promise.  That failure, coupled with the increase in deportations that marked his early years in office, has alienated many of the Latino leaders who helped get him elected, including several House lawmakers, like Rep. Luis Gutiérrez (D-Ill.), who’ve taken the rare step of picketing the White House.

6.  However the court rules, the decision is sure to animate the already intense, and very partisan, fight over immigration reform on the presidential trail that could prove crucial to the outcome of the race.

The number of eligible Hispanic voters is expected to top 27 million this year, according to the Pew Research Center, and those voters could be the difference in a number of battleground states, including Virginia, Florida, Colorado, Nevada and New Mexico.