If they decide the whole law has to be eliminated, several things could happen next depending on who wins the 2020 election, but none of it is good for the GOP.
Texas and several other states are arguing since the GOP tax bill set the mandate to $0, it's no longer a tax and therefore unconstitutional, and the whole rest of the law is unseverable and therefore should be struck down too.
The Texas law is saying that the ENTIRE LAW needs to be thrown out on a technicality. Even parts that have nothing to do with the mandate.
Congress clearly said the mandate is severable, because they severed it in 2017. Plus, the ACA still contains many taxes other than the mandate.
Let's look at, what WOULD happen if the ACA is struck down?
And Congress would be under IMMEDIATE pressure to pass a fix that will reverse this damage.
The House could pass a one-page bill that changes the mandate from $0 to $1. Boom, it's a tax again, and the whole law is valid once more.
These will change how the scenario plays out — but every one of these scenarios ends badly for Republicans.
In that case, it's easy. They can pass the fix within a week. It can be done as a budget bill, so the GOP can't filibuster it.
Now things get a little more complicated.
Dems will still pass their one-line fix in the House, but he'll ignore it.
The Dem president will keep calling on the Senate to pass the simple fix that will restore everything to the way it was. People will riot in the street. Mitch will eventually cave for fear of Senate gains in 2022 being blunted.
This is by far the most disastrous scenario for Republicans.
Imagine that, but ten times worse, and one year before a midterm.
I'm not totally sure Mitch even bothers proposing a compromise bill in that scenario. He might cave immediately.
But Dems should hope for it too. Because even if we benefit electorally from a bad SCOTUS ruling, thousands could die and millions lose their jobs.