34. Is the President's proclamation valid?

The Supremacy Clause (Article VI, Section 1, Clause 2) invalidates any state action that is contrary to validly-enacted federal law. This Clause ensures that the U.S. Constitution, and federal laws made pursuant to it, constitute the supreme law of the land. It prohibits states from interfering with the federal government's exercise of legislative and constitutional powers. When both a state and the federal government pass legislation in an area, the question of preemption arises. State laws can be preempted directly, such as when a federal law specifies that states may not pass laws in that area (called «express» preemption).

Under Article II, Section 2, Clause 2, the treaty power is granted to the President «by and with the advice and consent of the Senate, provided that two-thirds of the Senators present concur.» Like other federal law, treaties are the «supreme law of the land.» Any state action or law in conflict with a U.S. treaty is invalid (regardless of whether it is a state law or a state constitutional provision).

C is correct. The President's proclamation nullifying the state law under the treaty is valid because, just like any other federal law, a treaty is the supreme law of the land and will prevail as long as it is not otherwise unconstitutional.

A is incorrect. Although Congress does have the exclusive authority to specify legal standards for weights and measures, presidential treaties are still the supreme law of the land. Further, this is not an issue about which branch of government has the authority to specify weights and measures; the state law at issue requires all goods sold in that state to be packaged in traditional American sizes.

B is incorrect. This is an incorrect statement of the facts. The President is not invalidating the state law. The President is enforcing a treaty between the United States and a foreign country that authorizes the president of either country to issue a proclamation nullifying any state or local laws in that country that have the effect of impeding imports from the other country.

D is incorrect. This answer reaches the correct answer with the wrong reasoning. Although the proclamation is valid, it is not because the President has the inherent authority to nullify any state law that substantially impedes commerce with foreign nations. It is valid because, under the Supremacy Clause, it prevails over the conflicting state law, as stated above.