Final answer:
Once an appellate court has made a ruling, every state court in the country must follow the precedent established by that ruling. This principle is known as stare decisis.
Step-by-step explanation:
Once an appellate court has made a ruling, every state court in the country must follow the precedent. This principle is known as stare decisis and it means that judges are expected to rely on past decisions and their precedents when making decisions in new cases. Precedents establish the principles or guidelines that frame the ongoing operation of the courts and steer the direction of the entire legal system. While there may be flexibility and new precedents can be created, judges are generally reluctant to disregard precedent without justification.