Mexico is a democratic republic, consisting of thirty-one states and one federal district. Federal law is dominant in Mexico, and overrides state law in cases of conflict. Mexico's legal system is based on the civil law tradition. As in most civil law countries, the starting point for Mexican legal research is legislation, and at the federal level, the federal codes.
At the federal level, the government is organized into three branches: executive, legislative and judicial. The President of the Republic heads the Executive branch.
The legislative branch consists of a bicameral National Congress: the Senate and the Chamber of Deputies. The Congress discusses and approves legislation and ratifies presidential appointments.
The state governments are also divided into three branches: executive, legislative and judicial. The Governor applies the state laws. The legislative branch only has one chamber, the chamber of representatives.
Mexico has a federal and state court system. The Mexican Federal Judiciary is organized according to a three-tier system. At the apex is the Supreme Court. Three levels of circuit courts operate as the fedaral appellate courts. The individual district courts serve as the trial courts.
The states organize their courts along federal lines, although some of the smaller states do not have the intermediate appellate court.
For more information about the Mexican legal system and sources of law, see Brill's Foreign Law Guide.