Mexico has a single, streamlined law that ensures that foreign visitors and immigrants are:

In the country legally; have the means to sustain themselves economically

Not destined to be burdens on society

Of economic and social benefit to society

Of good character and have no criminal records; and contributors to the general well-being of the nation.

The law also ensures that:

Immigration authorities have a record of each foreign visitor;

Foreign visitors do not violate their visa status;

Foreign visitors are banned from interfering in the country's internal politics;

Foreign visitors who enter under false pretenses are imprisoned or deported;

Foreign visitors violating the terms of their entry are imprisoned or deported;

Those who aid in illegal immigration will be sent to prison.

The Mexican constitution strictly defines the rights of citizens -- and the denial of many fundamental rights to non-citizens, legal and illegal. Under the constitution, the Ley General de Poblacion, or General Law on Population, spells out specifically the country's immigration policy.