; and (B) licensed or certified to perform such service under applicable State law. (3) The term drug has the meaning given such term in section 201 of the Federal Food, Drug, and Cosmetic Act ( 21 U.S.C. 321 ). (4) The term State includes the several States, the District of Columbia, the Commonwealth of Puerto Rico, the United States Virgin Islands, American Samoa, Guam, the Northern Mariana Islands, each Indian tribe, and each territory or possession of the United States. (e) Severability If any provision of this Act, or the application of such provision to any person, entity, government, or circumstance, is held to be unconstitutional, the remainder of this Act, or the application of such provision to all other persons, entities, governments, or circumstances, shall not be affected thereby. (f) Rule of construction Nothing in this Act shall be construed to limit the fundamental right to travel within the United States, including the District of Columbia, Tribal lands, and the territories of the United States, nor to limit any existing enforcement authority of the Attorney General or any existing remedies available to address a violation of such right.