Final answer:
The most common Supreme Court decision is the published majority opinion, with at least five justices agreeing. The Court typically reviews less than 100 cases a year and often makes decisions that set legal precedents.
Step-by-step explanation:
What is the most common Supreme Court decision in a typical year?
The most common decision is the published majority opinion, where a majority of the nine justices agree. This means at least five justices support the decision, regardless of a unanimous vote. As the Supreme Court hears fewer than one hundred cases annually, each verdict can significantly influence American law and society. These decisions set precedents that future cases will refer to. A tied vote is rare, and in such cases, the decision of the lower court stands.
Moreover, the Supreme Court exercises its power by reviewing cases, often invalidating an average of 18 federal laws and 122 state laws per decade. Cases mostly reach the Supreme Court on appeal, specifically those involving constitutional questions or disparate law interpretations. The Justices use a writ of certiorari to select a small fraction of cases from the many requests each year, and public opinion can sometimes influence their decisions.
Decisions such as the Brown v. Board of Education and Roe v. Wade showcase the Court's role as a 'constitutional convention in continuous session.' Controversial cases can reveal political undercurrents and impact the Court's approval rating, as seen with landmark decisions like Bush v. Gore and decisions on the Affordable Care Act and same-sex marriage.