Ever since Judge Reed O’Connor of the Northern District of Texas ruled a year ago that the Affordable Care Act was unconstitutional, the country has been waiting for the next arbiter — a federal appeals court — to weigh in on the fate of the landmark health law.

On Wednesday, that ruling finally came. But it offered little clarity.

The judges from the Court of Appeals for the Fifth Circuit, in a 2-1 decision, ruled that one key element of the law — the mandate requiring people to have insurance — was unconstitutional. But they sent the rest of the case back to Judge O’Connor for what the dissenting judge called a “do-over,” asking him to give it another think on the question of whether other parts of the law should be struck down too.

The move means the legal showdown could continue for a long time, almost certainly beyond the 2020 election.

We spoke with three law professors who have closely followed the battles over Obamacare, to preview what next steps in this already prolonged litigation might look like.