Final answer:
The U.S. has federal and state courts due to federalism, with a dual court system allowing for the handling of different legal matters at both levels. The three-tiered federal court system follows precedent and conducts judicial review to maintain consistency and check other government branches.
Step-by-step explanation:
The reason the United States has both federal courts and state courts is due to federalism. The dual court system, comprising federal and state courts, is a result of the United States' federalist structure, which divides power between the national and state governments. In this system, the federal courts, including the U.S. Supreme Court, handle matters pertaining to federal law and the U.S. Constitution, while state courts handle matters under state law.
The federal court system operates on a three-tiered structure consisting of district courts, appellate courts, and the U.S. Supreme Court. Cases can ascend from the district courts to the appellate courts and potentially to the Supreme Court if they involve constitutional questions or significant federal issues. This system allows the courts to maintain consistency by following the doctrine of precedent, where past court decisions influence future case outcomes, ensuring a stable legal environment.
Moreover, the concept of judicial review, established by the landmark case Marbury v. Madison, allows courts to assess the constitutionality of legislative and executive actions. This reinforces the separation of powers among the branches of government, another fundamental principle of United States governance.