Justice Antonin Scalia's death clarifies the unusual importance of the 2016 election. President Obama took office with only one justice aged 80 or older. The next president will likely take office with two, plus an existing vacancy.

Obviously, every presidential election is enormously important. Without Barack Obama winning in 2008, Obamacare wouldn't have passed, and the EPA likely wouldn't have taken action on climate change. If Al Gore had taken office in 2001, the US almost certainly wouldn't have invaded Iraq.

But some elections prove more important than others — and one of the factors that decides the long-term effect of a presidency is the number of Supreme Court Justices they choose.

It's impossible to know for sure how many Supreme Court vacancies a given president will get, but the lower bound is usually zero. In 2016, the lower bound is not zero. It is one. It appears that Senate Republicans are preparing to take a position of total obstruction to any nominees President Obama might put forward:

And what Senate Majority Leader Mitch McConnell says goes. If he doesn't want there to be a vote on Obama's nominee, there won't be a vote on Obama's nominee. And even if he allows a vote, there's still a filibuster for the Supreme Court, unlike for lower courts. That means that Obama needs 60 votes to confirm his pick — and I highly doubt there are 14 Republicans willing to trade the Court's most reliable conservative vote for even a relatively moderate liberal.

That means that the Republicans will probably get their wish, and the choice will fall to the next president. And in all likelihood, not just that choice. Ruth Bader Ginsburg is 82 years old, has struggled with both colon and pancreatic cancer, and received a stent in her right coronary artery following heart trouble. Anthony Kennedy is 79, and also has a stent. Stephen Breyer is a relatively spry 77, but if the next president gets reelected will be 85 by the time their tenure is over.

The likely range for the next president is thus between one and four justices. If Hillary Clinton or Bernie Sanders is elected and have a Democratic Senate, they will be able to replace Scalia and possibly Kennedy with solidly liberal justices, ushering in a totally new era of Supreme Court jurisprudence that could see decisions like Citizens United overturned. If Donald Trump, Ted Cruz, Jeb Bush, Marco Rubio, John Kasich, or Ben Carson get elected, they will not only keep Scalia's seat in conservative hands, they will likely be able to replace Ginsburg and possibly Breyer too, moving the Roberts court even further to the right.

What a Democratic or Republican victory means for the court

The stakes for the Court aren't always this obviously huge. When Obama was elected, it was pretty obvious he'd get to replace John Paul Stevens, who was already 88. But Ginsburg was only 75, Kennedy and Scalia only 72, Breyer only 70, and David Souter only 69. It was very possible that Obama could've replaced Stevens and no one else.

But the stakes of this election for the court are clear, and enormous. A Supreme Court with six solid liberals — Democrats' best-case scenario — could overturn Citizens United, overrule Heller (which established for the first time that the Second Amendment gives individuals a right to bear arms), and enable school desegregation plans the Roberts Court struck down. It could conceivably, depending on its exact composition, abolish the death penalty for good, maybe even solitary confinement too.

And a Supreme Court with seven solid conservatives — Republicans' best-case scenario — could overturn Roe v. Wade, strike down even more campaign finance regulation, and narrow or abolish Miranda rights (as Scalia and Thomas once tried to do). If justices with a libertarian bent get appointed, you could even see a partial return of the Lochner era, with minimum wage statutes and worker protections getting struck down as violating "liberty of contract." That Supreme Court would almost certainly have invalidated Obamacare.

These are very very high stakes indeed. And they matter not just for the presidential election, but for highly contested Senate elections in states like Wisconsin, Illinois, New Hampshire, Ohio, and Florida. A vote for Republican incumbent Kelly Ayotte in New Hampshire becomes a vote for the conservative vision of the court. A vote for her Democratic rival Gov. Maggie Hassan becomes a vote for the liberal vision.

Reasonable people can disagree about the propriety of Senate Republicans punting the Scalia vacancy to the next president. But the fact that they've done so makes this election a referendum on the Supreme Court. Do you want a Court that allows governments to crack down on money in politics and guns and that limits the power of police and prosecutors? Or do you want a court that empowers law enforcement, paves the way for states to ban abortion outright, and limits the federal government's Commerce Clause powers to regulate the economy?

Usually these are treated as questions for the nine justices. But they are also questions for every American voter — and this year more than most.