Once the Court decides to hear a case (i.e., grants certiorari), each side submits a written brief, explaining how they want the Court to decide their case and the best arguments in support of that decision. The lawyers who craft the brief provide arguments they hope will convince the justices. An important part of their legal brief involves pointing out similar cases the Court has already decided and noting how the decisions in those cases (precedents) support their argument.

During this hour-long argument, which is open to the public, each side has 30 minutes to present its case to the justices. The justices, who have already read the briefs and studied the case, ask many tough questions that take up most of the allotted time.

Once the oral argument is completed, the justices meet in conference to discuss their ideas about the case. At the conference, the justices take a preliminary vote to either uphold or reverse the lower court decision. This is also an opportunity for them to discuss their reasoning. If the justices all agree on the outcome and the reasons, they issue a unanimous ruling. If they disagree on the case, they issue a majority opinion and a dissenting opinion. Either way, the majority or unanimous opinion is the ruling of the Court and becomes law. Sometimes, some justices agree with the outcome, but not with all the reasoning. In that case, those justices might issue a separate concurring opinion.