How are implied powers primarily justified?

Implied powers are primarily justified through the Elastic Clause, which is found in Article I, Section 8 of the U.S. Constitution. This clause grants Congress the authority to make all laws that are "necessary and proper" for executing its enumerated powers. The Elastic Clause allows for flexibility and adaptability in legislation, enabling Congress to create laws that address contemporary issues not explicitly mentioned in the Constitution.

This clause supports the idea that the federal government can take actions that are not specifically outlined in the Constitution, as long as they are in service of its constitutional responsibilities. For example, the establishment of a national bank was deemed constitutional under the Elastic Clause, as it was considered necessary for managing the country’s finances, even though the Constitution did not explicitly grant the power to create a bank.

Other options like the Supremacy Clause, which establishes that federal law takes precedence over state laws, and judicial review, which allows courts to interpret the Constitution and assess the legality of laws, play important roles in the functioning of government but do not specifically relate to the justification of implied powers. State legislation is also not relevant in this context, as implied powers pertain directly to the federal government's scope of authority based on constitutional interpretation.