Why is there tension between the Necessary and Proper Clause and the Tenth Amendment of the U.S. Constitution?

Perceived tension between the so-called Necessary and Proper Clause and the Tenth Amendment of the United States Constitution is largely illusory. The perception that such tension exists comes from a misconstrual of the scope of the clause.

The United States Constitution forms a federal government of enumerated powers. What this means is that the powers of the federal government are limited to those powers granted to the federal government by the Constitution itself. Thus, every clause of the Constitution is constrained by the very nature of the document itself, and thus each clause must be understood within the limitations of the powers granted under the document. The so-called Necessary and Proper Clause is no exception.

At the time the Constitution was in the process of being ratified, the clause in question raised concerns regarding its seemingly sweeping nature. However, the Federalists argued that the clause was merely a catch-all to make sure that the U.S. Congress, and by extension the federal government, could effectively wield the powers enumerated in the Constitution. Given the actual language of the clause itself, the Federalist position proved to be persuasive.

The Necessary and Proper Clause (Article 1, Section 8, Clause 18) reads:

[Congress shall have the power] To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.

The clause does not, nor was it ever intended to, give the Congress the power to pass laws it feels are necessary and proper in a general sense. Rather, the clause gives Congress the power to make laws that are “necessary and proper” to exercise “the foregoing Powers” and “all other Powers vested by this Constitution in the Government of the United States”. Thus, the clause is constrained by the powers listed above Clause 18 in Section 8 of Article 1, as well as the powers, and restrictions, of the rest of the Constitution.

One such restriction is the Tenth Amendment. The Tenth Amendment reads:

The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.

The Tenth Amendment serves to strengthen the already existing grants of powers and limitations thereof as provided in the rest of the Constitution. It helps ensure that the principle of enumerated powers is held strictly against the federal government so that it does not exceed its power. With regard to the Necessary and Proper Clause, the Tenth Amendment becomes part of the constraints of that clause, namely that the clause allows congress to pass laws necessary and proper for the exercise of powers granted under the Constitution.