Even before the sudden death of Justice Antonin Scalia, this was going to be an enormously consequential Supreme Court term.
The court has heard or has agreed to hear cases involving the constitutionality of considering race in college admissions; how far states can go in restricting abortion; the viability of public sector unions; whether President Obama could defer deportations of unauthorized immigrants; and the tension between claims of religious freedom and women's access to contraception.
The high court recently stepped in to halt implementation of President Obama's climate plan.
Click through images of Justice Antonin Scalia:
Now, all of the cases on the court's docket are thrown into question, particularly as top Republicans like Senate Majority leader Mitch McConnell have declared that the Senate should wait to confirm a replacement until a new president is in office.
If the court of eight justices splits 4-4, the opinion of the federal appeals court stands without making law for the rest of the country, according to Samuel Bagenstos, a law professor at the University of Michigan who clerked for Supreme Court Justice Ruth Bader Ginsburg and has argued before the court several times.
The justices generally vote for a case's outcome at a conference after oral argument, after which the chief justice assigns an opinion — but if Scalia was the deciding fifth vote in a case that has already been heard, that result is negated.
"Unless a justice is sitting at the court at the time of argument and at the time the decision is issued, the justice's vote doesn't count," Bagenstos said.
In Whole Woman's Health v. Hellerstedt, the court's biggest abortion case in decades, the 5th U.S. Circuit Court of Appeals ruled against the abortion clinics in upholding parts of a Texas law requiring doctors performing abortions to have admitting privileges at nearby hospitals. It resulted in the shutdown of dozens of abortion clinics.
The 5th U.S. Circuit Court of Appeals voted to temporarily block President Barack Obama's executive action of deferring the deportation of some undocumented immigrants. The Supreme Court was expected to hear arguments in April. The plan could shield more than 4 million people from deportation.
The group of religious nonprofits before the Court in a case consolidated as Zubik v. Burwell, who object to the Obama administration's plan for providing contraception to women whose employers object, all lost at their respective lower courts, though other organizations not technically before the Court prevailed at the 8th U.S. Circuit Court of Appeals.
Another possibility, said Bagenstos, is for the cases to be re-argued in the next term. But, he said, "In the absence of new justice joining the court, that would be very unlikely."