What legal theory supports a state's right to invalidate federal laws deemed unconstitutional?

The legal theory that supports a state's right to invalidate federal laws deemed unconstitutional is nullification. This concept arises from the belief that states have the authority to reject federal laws when they believe those laws violate the Constitution. Nullification is rooted in the idea that the Constitution is a compact among sovereign states, which grants them the power to assess the legality of federal actions.

Historically, nullification gained prominence in the early 19th century, particularly with the Nullification Crisis of the 1830s when South Carolina attempted to nullify federal tariffs. The argument for nullification suggests that states can act as a check on federal power, thereby protecting individual liberties and state sovereignty.

Other choices, while relevant to federal-state relations, do not specifically pertain to the concept of invalidating federal laws. Federalism describes the division of power between national and state governments but does not inherently grant states the authority to nullify federal laws. Secession refers to a state's withdrawal from the Union and is not about the invalidation of specific laws but rather about the overall relationship between the state and the federal government. Constitutionality pertains to whether a law aligns with the Constitution but does not specifically address the state's role in invalidating federal laws.