Labrum - a cover which may be loosely referred to as the upper lip. Mandibles - hard, powerful cutting jaws. Maxillae - 'pincers' which are less powerful than the mandibles. They are used to steady and manipulate the food. Labium - the lower cover, often referred to as the lower lip.
The President, as head of the federal executive branch, is ultimately in charge of enforcing the immigration laws of the United States. In turn, he must make discretionary decisions about whether and when to prosecute immigration law violators through deportation and other sanctions.
Opponents of sanctuary cities argue that cities should assist the federal government in enforcing immigration law. Supporters of sanctuary cities argue that enforcement of federal law is not the duty of localities. Legal opinions vary on whether immigration enforcement by local police is constitutional.