Refuse means to decline or reject something. In the context of government, it refers to the act of states choosing not to comply with federal laws they believe violate the Constitution.
Related terms
Nullification: Nullification is when states declare a federal law null and void within their borders because they believe it violates the Constitution.
States' Rights: States' rights refer to the idea that individual states have certain powers and authority separate from the federal government.
Supremacy Clause: The Supremacy Clause is a constitutional principle stating that federal law takes precedence over state laws when there is a conflict between them.