“If you picture severability being like a Jenga game — it’s kind of, if you pull one out, can you pull it out while it all stands? Or if you pull two out, will it still stand?” Barrett explained during Wednesday’s questioning.

“The presumption is always in favor of severability,” she said.

Severability is a question of congressional intent — whether Congress still would have passed the rest of a law if it knew it couldn’t have the piece the courts are striking down. And conservative judges make a point of relying only on a law’s text when determining congressional intent.

That should make the current case easy, the blue states defending the ACA argue: Congress zeroed out the mandate and left the rest of the law intact — a pretty clear sign that it intended for the rest of the law to operate in the absence of the mandate.