The Senate Judiciary Committee voted to approve President Donald Trump‘s Supreme Court nominee Neil Gorsuch on Monday, bringing a confirmation vote closer to the full Senate. But it also became clear that Democrats have the votes to filibuster his nomination. So what’s next?

Sixty votes are required to overcome a filibuster, and it doesn’t look like Republicans have those votes. That means Republicans would likely have to invoke the “nuclear option.” That’s Capitol Hill-speak for amending long-standing Senate rules requiring a 60-vote threshold to confirm Supreme Court nominees, which would allow the GOP to install Gorsuch with a simple majority vote.

It is almost certain that such a move would result in Gorsuch’s confirmation to the Supreme Court. But it would also mark the first time the option was ever used on a Supreme Court nominee, and could forever change the confirmation process for the high court.

Here’s what you need to know about the obscure rule that could determine the future of the Supreme Court, and possibly the Senate.

What is the Nuclear Option?

It’s a Senate procedure that allows the current leader of the Senate to change the voting rules, in this case for the confirmation of a Supreme Court Justice, from 60 votes, or a “super majority,” to a simple majority, or 51…