While you can never be certain as to what the Supreme Court would do, I’ve always felt that it is most likely that they would ultimately find that King v. Burwell is a frivolous case. (In other words, the most conservative justices might accept it, but John Roberts will cast the deciding vote against it if needed). This case is the latest Republican attempt to overturn the Affordable Care Act in the courts because of some language in the law, contradicting other portions, which could be taken to mean that subsidies are only available to those who obtain coverage through state exchanges, and not the federal exchange.
As I’ve pointed out in the past, it would politically be bad for Republicans if the court ruled against the Obama administration in this case. If the Supreme Court does accept the absurd argument that subsidies should only be available under the law for policies purchased on state exchanges, the simplest solution would be for Congress to revise a few words in the law to fix the problem. It is rather common for Congress to pass laws after major legislation to fix minor problems, except in this case Republicans in Congress are more interested in repeated, futile efforts to repeal ObamaCare as opposed to making such fixes–with yet another repeal vote now planned.
The Kaiser Health Tracking Poll for January finds that relatively few people are now aware of King v. Burwell, but most people do think that Congress should fix the problem. Among total voters, passing a law to fix this is supported 64 percent to 27 percent. There is similar support among independents, greater support among Democrats, and even a substantial number of Republicans (40 percent) would support such a fix:
If this is not fixed by Congress passing such a law, the second solution would be for states to start their own exchanges. A majority would also support this in affected states. Even Republicans support this, although at lower levels than Democrats and independents:
I suspect that Republican leaders would much prefer to see the Supreme Court not put them in a position to have to take such action, either in Congress or at a state level. Failure to take such action would make displease the majority of voters, while taking such action would displease their base, who might take revenge in primaries where they dominate.
Update: Hospitals and insurance companies also lose if the subsidies are not continued, and are therefore also defending the subsidies before the Supreme Court.