The United States and Mexico may share a common border, commerce and a constant flow of people crossing that border, but the laws governing both nations differ greatly. The US system is based on common law, which comes from England, and the Mexican system is based on Roman or civil law, practiced in Spain. Before going over the differences, let's see some of the similarities:
Federalist system. Both countries are divided into states
Presidential system. Neither country has a prime minister
The president is commander in chief
The Supreme Court is used as a last resort
Mexico is less litigious than the US. Parties are more likely to negotiate than sue
There are no juries
A party cannot appear without an attorney except in family law
Courts close for several government holidays. Judicial Branch takes a 3-week vacation in August and a two-week Christmas holiday. US courts are closed for 13 national holidays.
The president and state governors can only serve one term of six years.
States have much less power
The president is elected by popular vote instead of an electoral college (Hillary Clinton would have liked that!)
As civil law and not common law is used in Mexico, the Supreme Court is less powerful there
The Mexican constitution is not as simple as in the US where amendments are short and easy to understand. Mexico uses articles which are somewhat long and complicated, 136 of them, whereas the US constitution has 27 amendments
If you need to know more in depth about Mexican laws, consult a qualified Mexican lawyer.