Drug liberalization is the process of eliminating or reducing drug prohibition laws. It also authorized Congress to enact legislation enforcing this prohibition. The DiGiovanni family directly benefited from this lack of enforcement of prohibition laws. Many immigrants openly flouted Mexican law, especially the prohibition against slavery. Terms contrary to public policy, or in conflict with a statutory prohibition are not enforced. Barr advocated complete federal prohibition of medical marijuana. The dates for the repeal of prohibition are often debated. Anyone who violates this prohibition will be punished. Their efforts eventually led to the repeal of prohibition. Upon repeal of national prohibition, 18 states continued prohibition at the state level. The constitutional prohibition on multiracial political parties was lifted. Where it is legislated against the degree of prohibition also varies. Total lack of respect for any prohibition, any authority. Furthermore, American geography contributed to the difficulties in enforcing Prohibition. Amnesty International supported the UN treaty on the Prohibition of Nuclear Weapons.