Republicans are gearing up to jam through a successor and Democrats are howling about hypocrisy -- because after Justice Antonin Scalia died in early 2016, Republicans refused to consider then-President Barack Obama's nominee, because it was too close to a presidential election.
Here's what we know about what happens next, and why it matters.
What happens next?
President Donald Trump has to make a pick. He said Monday that he plans to announce his selection as soon as Friday.
Who's on the short list?
Trump recently released a short list of candidates but has said he'll pick a woman to replace Ginsburg, the second woman to join the court. Judges Amy Coney Barrett and Barbara Lagoa are seen as the top contenders.
Then what happens?
Whoever is chosen will have to go through a Senate process, including public hearings. Then there's a committee vote. And then there's a Senate floor vote.
Even without a nominee, the Senate is gearing up to put that process in motion, potentially before Election Day -- though, ironically, the last nomination to succeed with a less-than-two-month confirmation process was Ginsburg's, back in 1993.
How many votes does it take to confirm a new justice?
Republicans ended the filibuster for Supreme Court nominees, so it takes only a simple majority. Vice President Mike Pence can break a 50-50 tie, which might happen if three Republicans decide they won't vote for Trump's nominee.
What if a confirmation doesn't happen before the election?
Key Republican senators have said they won't support holding hearings before Election Day. (More on that in a second.) But a new Congress takes office January 3, so the current Senate, with the current Republican majority, has only until then to confirm a Trump nominee. Trump, however, remains in office until January 20 at noon, so a new Republican majority could also confirm a Trump pick in the new year even if he loses.
What if Republicans lose the Senate in November? Can they still vote after the election?
Absolutely. That's true even if Democrats win the White House and the Senate -- anytime before January 3, the current Senate Republicans can still go ahead and confirm a conservative nominee. That would sew up a very conservative majority on the Supreme Court for a generation or more.
Republicans currently control the White House. Shouldn't they get to nominate whoever they want?
Technically, yes. According to the Constitution, the president appoints Supreme Court justices and the Senate approves the pick.
What difference does it make, practically, if Trump gets another justice?
There are several major cases on the docket already. Here are two ways in which a conservative majority could likely have an almost immediate impact:
1. The Affordable Care Act -- Obamacare, which dramatically expanded Americans' access to health insurance coverage, has narrowly withstood several court challenges. It's currently facing another one. The law has survived only because a conservative justice, Chief Justice John Roberts, has sided with liberal judges.
But the Trump administration has gotten behind a coalition of several states currently challenging it. Arguments are scheduled for shortly after the election. A conservative majority could overturn the law, which Trump and other Republicans currently have no plan to replace.
2. Abortion -- When Republicans sat on that vacant seat in 2016, preventing Obama from naming Merrick Garland to the bench and giving Trump a seat to fill as soon as he took office, it changed the balance of the court in a way that will threaten the landmark 1973 Roe v. Wade decision that legalized abortion in the US.
If a conservative replaces Ginsburg, it will take two Republican-appointed swing votes to protect the Roe decision. Otherwise, there's a good chance abortion will be outlawed in many US states.
Who will be the key senators to watch?
Two Republicans, Sens. Susan Collins of Maine and Lisa Murkowski of Alaska, have already said the next president -- Trump or his Democratic rival, Joe Biden -- should pick the nominee. That means McConnell can lose one more Republican and still have Pence break a tie. (That's also assuming all Democrats vote "no" on principle.) Here's our latest report on the state of play in the Senate.
Are there other Republicans who might vote against a Trump nominee?
Several had said previously that they'd oppose a nominee in 2020 after opposing a nominee in 2016. But minds can change! This is why people don't love politicians.
Sen. Lindsey Graham of South Carolina has changed his already. He had said before Ginsburg died that he'd oppose an election-year nomination. Now he supports filling the seat. So go figure. He chairs the Senate Judiciary Committee and would lead any hearings. But he's also running for reelection and is a top supporter of Trump's.
Sen. Chuck Grassley of Iowa had also said he would oppose an election-year nomination. Now he's signaling that he might not.
And Sen. Mitt Romney of Utah said Tuesday that he's open to a vote this year, paving the way for a quick confirmation. "The historical precedent of election year nominations is that the Senate generally does not confirm an opposing party's nominee but does confirm a nominee of its own. The Constitution gives the President the power to nominate and the Senate the authority to provide advice and consent on Supreme Court nominees," Romney said in a statement. "Accordingly, I intend to follow the Constitution and precedent in considering the President's nominee. If the nominee reaches the Senate floor, I intend to vote based upon their qualifications."
We're just talking about one Supreme Court nominee.
Ginsburg was 60 when President Bill Clinton picked her in 1992. She was the oldest person to have been successfully nominated to the Supreme Court in decades.
Most justices are in their late 40s or early 50s when they're nominated. Trump's top two potential picks, Barrett and Lagoa, are 49 and 52, respectively. But he's also said to be eyeing Allison Jones Rushing, who is still in her 30s.
Any of these women, if they serve until they're 87 like Ginsburg, would be on the court for 30- or 40-plus years, along with Trump's other two justices, Neil Gorsuch and Brett Kavanaugh, who are both in their early 50s.
But do most Supreme Court justices serve that long?
The average length of a Supreme Court tenure has grown a lot. Harvard Business Review did an actuarial analysis in 2018 and argued the average tenure over the next 100 years will grow to 35 years. It was 17 over the previous 100 years. That also means there will be fewer and fewer of these nominees, which is why Republicans will do everything they can to put a young justice in now.
Why don't justices retire more strategically?
They do, actually. Justices have increasingly tried to time their retirements. Republican-appointed justices tend to wait for Republican presidents -- like Anthony Kennedy, who retired in 2018.
Ginsburg wanted the first female president to pick her replacement, so she declined to retire during the Obama administration, hoping that Hillary Clinton would get to name a successor. Instead, Ginsburg died on the bench with just enough time for Trump to appoint a successor.
The same thing could have happened with Scalia, the Republican-appointed justice who died at the end of Obama's term. But because McConnell refused to even allow a hearing on Obama's nominee to replace Scalia, the court's conservative majority was protected.
What about the idea that the American people should have a say in all this?
We live in a republic, where the Electoral College picks the president and senators confirm Supreme Court justices. And we are, increasingly, governed by people who represent a minority of Americans. That will continue on the court for a long time. CNN senior political analyst Ron Brownstein has a very thoughtful piece on this undemocratic element of US democracy.
Could and should the court be changed?
That's going to be a controversial question, but one that will have to be addressed -- especially if Republicans lose either the White House or the Senate and still go ahead and confirm a new justice before January.
During the Democratic primary in 2019, several Democrats, including now-vice presidential nominee Kamala Harris, showed interest in plans to increase the number of justices on the court.
There are also proposals to put term limits on individual justices or on each seat. This would insure some turnover.
But doesn't the Constitution say justices serve life terms?
Not technically. It gives Congress the ability to set the makeup of the court. And its words have been interpreted to give justices life terms. But the actual words are different, saying justices shall serve during times of "good behavior." It doesn't list a term or an end date, so one has never been applied. That doesn't necessarily mean it couldn't. But how this would be accomplished would be up for debate.
Here's the relevant language from Article III:
The judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behaviour, and shall, at stated Times, receive for their Services, a Compensation, which shall not be diminished during their Continuance in Office.
What about changing the size of the court?
This could more easily be accomplished. The size of the court went up and down pretty regularly during the first 100 years of the US. But it's been set at nine since the 1860s. Franklin D. Roosevelt tried and failed to expand the court to 15 justices in the 1930s. Several Democrats, notably Pete Buttigieg, were pushing a similar idea during the recent presidential primary. The most important Democrat right now, Biden, has said he opposes it.
Do we know how most Americans feel?
Supreme Court vacancies are usually more of a motivator for Republican voters than for Democratic ones. That may not be the case this year, with Democrats still frustrated that Obama's nominee was denied a hearing or a vote.
And regarding how people feel about an election-year vacancy, we have conflicting reports. In a Marquette University poll conducted just before Ginsburg died, a majority said Republicans should be able to fill a hypothetical vacancy on the court. Conversely, in a Reuters/Ipsos poll conducted in the two days after Ginsburg died, a majority said the next president should pick.
This story has been updated with more details about the confirmation process.