Final answer:
The ruling establishes the doctrine of implied powers and the principle of national supremacy, influencing federal over state law, impacting cases like United States v. Fields.
Step-by-step explanation:
The main idea in this ruling is the establishment of the doctrine of implied powers and the principle of national supremacy. The doctrine of implied powers grants Congress discretionary power to fulfill its constitutional duties, while the principle of national supremacy asserts that federal laws take precedence over conflicting state laws. This principle directly affects cases like United States v. Fields wherein federal law would trump state law in areas of conflict, ensuring consistent application of the law across all states. These principles help address disparities in the application of laws, such as those regarding marijuana usage, by emphasizing the authority of federal law. Considering the extended impact on immigration policies as seen in the Supreme Court decision in Arizona v. United States, federal rulings have substantial influence on ensuring a uniform application of law across the nation.