What's EMTALA, the patient protection law at the center of Supreme Court abortion arguments?

The Supreme Court will hear arguments Wednesday in a case that could determine whether doctors can provide abortions to pregnant women with medical emergencies in states that enact abortion bans. The Justice Department has sued Idaho over its abortion law, which only allows a woman to get an abortion when her life, not her health, is at risk. The state law has raised questions about when a doctor is able to provide the stabilizing treatment that federal law requires. The federal law, called the Emergency Medical Treatment and Active Labor Act, or EMTALA, requires doctors to stabilize or treat any patient who shows up at an emergency room.