Of interest recently was Maine’s cigarette labeling law.  It is generally understood, and well documented in the CIPP references, that federal regulations define a baseline.  If a state law exists after passage of a federal act, the state law must either be struck from books, or rewritten to comply with the new legislation.  However, if the state wants to define more stringent regulations (think California and car emissions), that is their prerogative under State’s Rights.  Maine did just that protecting their state consumers with additional cigarette warning labels, and the cigarette manufacturers brought suit.  The Supreme Court upheld Maine’s consumer protection law resulting in an additional win for courageous states.