Justice Antonin Scalia’s death will have an immediate effect on some of the country’s most contentious legal questions, undercutting conservative hopes of winning sweeping victories in pending U.S. Supreme Court cases on abortion, immigration, affirmative action and unions.

Scalia, a larger-than-life figure and judicial hero to legal conservatives, would probably have voted against the Obama administration and its allies on each of those issues. His death at age 79 all but dashes hopes that conservatives can put together a five-justice majority.

Exactly what that means will depend on the case. The clearest impact may come in the union dispute, which has threatened to end requirements that public-sector workers in 20-plus states pay fees to their collective-bargaining representatives.

Scalia’s absence means that, even if union foes can win over swing justice Anthony Kennedy, they probably won’t do better than a 4-4 split. That would affirm a lower-court ruling backing labor unions, without setting a nationwide precedent. It would also leave intact a 1977 Supreme Court ruling allowing mandatory fees, a decision union opponents were hoping to overturn.

"What might previously have been a 5-4 ruling against fair-share fees could now be a 4-4 ruling affirming the lower court’s pro-union decision," said Elizabeth Wydra, president of the Constitutional Accountability Center, which backs the union in the case.

Scalia, a 1986 nominee of President Ronald Reagan, was a core member of the conservative wing of the court, which is now evenly divided between Republican and Democratic appointees.

Undocumented Immigrants

The court could still block President Barack Obama’s plan to defer deportation for millions of undocumented immigrants. In that case, a lower court ruled against Obama, so a 4-4 split would leave in place a bar on the plan.

Still, the Supreme Court wouldn’t be able to issue a ruling that would put broader limits on presidential authority. The justices flagged that possibility last month when they said they would consider whether Obama had violated his constitutional duty to "take care that the laws be faithfully executed."

A 4-4 split in the immigration case would also leave open the possibility that a different federal appeals court could uphold the plan. That could leave legal uncertainty, possibly with the plan in effect for only part of the country.

Similarly, in the Supreme Court’s abortion case, a federal appeals court largely upheld Texas’s regulations on clinics. Although the justices could still affirm that ruling with a 4-4 vote, abortion foes wouldn’t win a broader ruling that would give states across the country more freedom to enact restrictions.

Affirmative Action

The outlook on affirmative action is complicated because the court was already operating short-handed. A federal appeals court upheld racial preferences in admissions by the University of Texas, and opponents are hoping the Supreme Court will reverse that ruling. Justice Elena Kagan, one of the court’s four Democratic appointees, isn’t taking part in the case because she was involved in the litigation as an Obama administration lawyer.

Scalia’s death now means the court could vote 4-3 against the program, giving opponents of affirmative action a majority, but one that would be unusually vulnerable to being overruled once the court is at full strength. His absence even raises the possibility that the court’s liberal wing could win the case 4-3 by securing Kennedy’s vote.

Scalia’s absence may also hurt the chances for conservatives in cases involving state legislative redistricting and religious objections to contraceptive coverage under the Obamacare health-insurance law. In both instances, conservatives were counting on Scalia’s help in overturning lower court rulings.

The union-fee, affirmative action and redistricting cases have already been argued and, under the court’s usual procedures, put to a private vote among the justices. Those votes, however, are preliminary and don’t count until an opinion is released, said Jonathan Adler, a constitutional law professor at Case Western Reserve University in Cleveland.

For "any of these cases that would have been 5-4 with Justice Scalia in the majority, resolution of the underlying issues will have to wait for another day," Adler said.