The sudden death of Justice Antonin Scalia will have an immediate impact on numerous cases now pending before the Supreme Court, including several that were expected to split along ideological or political lines with 5-4 votes.
Instead, some of those votes now could deadlock, 4 to 4, meaning a lower court's last ruling on the issue will stand.
Here are some of the key cases this term and what might happen.
Friedrichs vs. California Teachers Assn.
The court was set to decide whether to overrule a 1977 decision and prohibit unions from charging mandatory fees to nonmembers, including school teachers. If the court splits 4 to 4, the deadlock will keep in place laws in California and 22 other states that permit these mandatory fees to cover the cost of collective bargaining.
Fisher vs. University of Texas
The court was set to rule on whether a university can give an edge in admissions to black and Latino students.
Because Justice Elena Kagan was already recused from the case, the court's conservatives could still have an edge, with a 4-3 vote to cut back on college affirmative action.
Whole Woman's Health vs. Hellerstedt
The court in early March is set to hear a case testing whether conservative states such as Texas can adopt stringent medical regulations that would force many abortion clinics to close down.
A U.S. appeals court upheld the state's regulations, but then the justices blocked them from taking effect by a 5-4 vote, with Justice Anthony M. Kennedy in the majority and Scalia in dissent.
If Kennedy joins with the four liberals, the court could strike down the Texas regulations by a 5-3 vote. But if he joins with the conservatives to rule for Texas, the court would be split 4 to 4 and unable to issue a ruling.
Zubik vs. Burwell
The court has agreed to decide whether Catholic charities and other religiously affiliated groups may opt out of providing employees certain contraceptives, including what they believe are "abortion-inducing" drugs.
This was seen as major test of religious liberty. But without Scalia, the court may be split 4 to 4 and unable to rule. Most courts across the nation have ruled for the Obama administration and upheld the "contraceptive mandate" on the grounds that the religious entities are not required to pay for the disputed drugs.
Evenwel vs. Abbott
The court is considering a case that could shift how voting districts are drawn. Conservative challengers said the current system that relies on counting all people discriminates in favor of areas that have a large percentage of immigrants, children, prisoners and others who are not citizens or not eligible to vote.
Without Scalia on the court, the conservative lawyers who brought the case are unlikely to prevail.
United States vs. Texas
The court in April planned to hear the Obama administration's appeal of a Texas judge's order that blocked the president's executive action authorizing deportation relief and work permits for more than 4 million immigrants who are living here illegally.
If Kennedy were to join with the court's four liberals, they could set aside the judge's order and allow President Obama's plan to take effect in his final months in office. However, if Kennedy votes with the three remaining conservatives to say Obama's order was illegal, the court would be deadlocked, thereby keeping the judge's order in place and blocking Obama's program from taking effect.
Follow @DavidGSavage on Twitter