The case was originally brought by a group of Republican state officials, who argued that changes to the Affordable Care Act made by Congress in 2017 rendered the law’s requirement that most Americans obtain health insurance unconstitutional. The Trump administration took the side of the state officials, and together they have argued in court that, without the so-called individual mandate, the rest of the major health care law should also be erased.

A Federal District Court judge in Texas agreed, ruling all of Obamacare invalid, but postponed the effects of his ruling until the case could be appealed. In that ruling last month, the Fifth Circuit Court of Appeals found that the mandate could not remain, but declined to rule on what should happen to the remainder of the health law, asking the lower court to reconsider the question in more detail.

Under a normal process, the case would take months, if not years, to reach the Supreme Court. But the Democratic states and the House, which intervened in the case to defend the health law, are asking the Supreme Court to review the Fifth Circuit’s ruling immediately.

There are effectively three paths forward for the case. The Supreme Court could reject it, letting the lower courts continue their work. It could accept it, and grant the litigants’ request for “expedited review,” setting up a ruling on the case this session. Or it could accept the case on its typical schedule, which would most likely mean oral arguments and a ruling in its session that begins in the fall. Four justices would need to agree to accept the case, but it would take a majority vote of five to speed up the case’s consideration.

If the current lower court ruling from Texas is ultimately upheld, the case could have major consequences throughout the health care system. Estimates from the Urban Institute suggest that around 20 million more Americans would become uninsured. And a wide range of federal health policies, including consumer protections, payment reforms, drug approval processes and fraud penalties, would have to be unwound.