When conservative Justice Antonin Scalia died unexpectedly just ahead of the presidential primaries, it made the Supreme Court a focal point of the presidential race.
Donald Trump promised that he will fill Scalia's seat with someone of a similar ideological bent. He released a list of potential appointees who meet his requirements, which include favoring gun rights and overturning Roe vs. Wade.
"I am looking to appoint judges very much in the mold of Justice Scalia. I'm looking for judges — and I've actually picked 20 of them so that people would see," he said during an Oct. 9, 2016, debate.
WHY HE'S PROMISING IT
Before Scalia's death, the nine-justice court was relatively balanced — with four consistent liberals, four consistent conservatives, and Anthony Kennedy, who is conservative but occasionally sides with the liberal justices.
President Barack Obama's choice to replace Scalia, Merrick Garland, would have given the court a left-leaning edge. So Republicans in Congress refused to consider Garland, in hopes that a Republican would win the White House and appoint someone more conservative.
During the campaign, some Republican leaders who didn't care for Trump said they would support his candidacy regardless because of the open Supreme Court seat.
WHAT NEEDS TO HAPPEN
Trump is expected to follow the standard process of appointing a Supreme Court justice. He will announce his nominee; the Senate will hold hearings to vet him or her; and the Senate will vote on whether to confirm.
WHAT'S STANDING IN HIS WAY
Trump won't face nearly the same challenge Obama did because when he becomes president because the Republican Party will control both the White House and Congress.
But Democrats have vowed to put up a fight.
"We are not going to settle on a Supreme Court nominee," said Senate Minority Leader Chuck Schumer Jan. 3. "If they don't appoint someone who's really good, we're going to oppose him tooth and nail."
Supreme Court nominees have to clear a 60-vote threshold in the Senate. However, Republicans have just a 52-48 edge, so they will need support from at least eight Democrats. If the Republicans don't get that support, they might decide to remove the 60-vote requirement, which would be a significant change to Senate rules.
TIMELINE
Scalia's open seat has left the Supreme Court slightly handicapped with fewer than nine justices for almost a year. The eight justices have declined to take up several significant cases, out of concern that they would result in a 4-4 split decision.
So it's expected that Trump will make an appointment soon after taking office, and how long the confirmation process takes will depend largely on how the debate in the Senate unfolds.