Definition
Enumerated powers are the authorities the Constitution explicitly assigns to the federal government. Most are listed in Article I, Section 8, which sets out what Congress may do, such as taxing, borrowing, coining money, declaring war, and regulating interstate commerce.
The idea behind enumeration is that the national government holds only the powers granted to it. Powers not delegated to the federal government, and not forbidden to the states, are reserved to the states or the people.
Why it matters
How it works
When Congress acts, the action must trace back to an enumerated power, alone or combined with the Necessary and Proper Clause. Courts ask whether a statute fits within a granted authority such as commerce, taxation, or the war power.
In practice the boundaries are contested. Broad clauses like commerce have allowed Congress to reach far beyond a literal reading of the list, while critics argue for a narrower interpretation closer to the enumerated text.