(Bloomberg View) — We don't know whether the Supreme Court's decision in the King case will be to take away subsidies for people who signed up for insurance through healthcare.gov, the exchanges. If that is what happens, however, the legislative politics of a fix are increasingly clear.

The case is about whether Congress did or didn't authorize the Affordable Care Act to contain the same set of subsidies for people in states using federally run exchanges as it does for those in states that run their own exchanges. If the court rules against the Obama administration, millions of people in more than half of the states will lose subsidies and may drop their insurance. Even worse, if (as is likely) healthy people flee and those with immediate medical needs remain, the markets in those states could collapse as insurance companies raise premiums to make up for the lost customers.

So if Republicans win, they create an ugly mess. Moreover, it's a mess that could be completely fixed with a one-page bill that would make clear that subsidies are available in all states. But most Republicans don't want to pass a one-page fix; the whole point of the suit was to create the mess.