Politics

The United Mexican States are a federal presidential representative democratic republic whose government is based on a congressional system, whereby the president of Mexico is both head of state and head of government, and of a multi-party electoral system. The federal government represents the United Mexican States and is divided into three branches: executive, legislative and judicial as established by the Political Constitution of the United Mexican States, published in 1917. The constituent states of the federation must also have a republican form of government based on a congressional system as established by their respective constitutions.

The executive power is exercised by the executive branch, which is headed by the President, advised by a cabinet of secretaries and independent of the legislature. Legislative power is vested upon the Congress of the Union a two-chamber legislature comprising the Senate and the Chamber of Deputies. Judicial power is exercised by the judiciary, comprising of the Supreme Court of Justice of the Nation, the Council of the Federal Judiciary and the collegiate, unitary and district tribunals.

The politics of Mexico are dominated by three political parties, the National Action Party (PAN), the Party of the Democratic Revolution (PRD) and the Institutional Revolutionary Party (PRI).

Powers of the Union

The federal government, called the Supreme Power of the Federation, is constituted by the Powers of the Union: the executive, the legislative and the judicial powers. Mexico City, as the capital of the federation is the Federal District, the seat of the powers of the Union. All branches of government are independent; no two separate branches must be vested upon a single person or institution, and the legislative power must not be vested upon single individual.

Executive Branch

The executive power is vested upon a single individual, the president of the United Mexican States, elected by first-past-the-post plurality for a 6 year term (called sexenio), without the possibility of re-election. There is no office for a vice-president; in case of 'absolute absence' or incapacity of the President, the Congress of the Union (with a quorum of at least two-third of all representatives) will be constituted as an Electoral College which will elect by absolute majority an interim president. If the absolute absence occurred during the first two years of the sexenio, the Congress will also call elections in no less than 14 and no more than 18 months after the inauguration of the interim president. If the absolute absence of the presidents occurred during the last four years of the sexenio, then the interim president will serve for the remaining years of the absent president's term.

The President also appoints, with Senate approval, the Cabinet members and other officers. The President is responsible of executing and enforcing the law, and has the authority of vetoing bills.

Legislative Branch

The legislative power is vested upon the General Congress the Congress of the Union, a bicameral congress comprised of the Senate and the Chamber of Deputies. The powers of the Congress include the right to pass laws, impose taxes, declare war, approve the national budget, approve or reject treaties and conventions made with foreign countries, and ratify diplomatic appointments. The Senate addresses all matters concerning foreign policy, approves international agreements and confirms presidential appointments. The Chamber of Deputies addresses all matters pertaining to the government's budget and public expenditures.

The Chamber of Deputies is formed by 500 representatives of the nation. All deputies are elected in free universal elections every three years, in parallel voting: 300 deputies are elected in single-seat constituencies by first-past-the-post plurality (called uninominal deputies), and the remaining 200 are elected by the principle of proportional representation (called plurinominal deputies) with open-party lists for which the country is divided into 5 constituencies or plurinominal circumscriptions. Deputies cannot be re-elected for the next immediate term.

Being a supplementary system (PM) of parallel voting, proportionality is only confined to the plurinominal seats. However, to prevent a party to be overrepresented, several restrictions to the assignation of plurinominal seats are applied:

• A party must obtain at least 2% of votes to be assigned a plurinominal seat;
• No party can have more than 300 seats (uninominal and plurinominal together), even if the party gets more than 52% of the votes;
• No party can have more deputies (uninominal and plurinominal) whose proportion in the Chamber is 8 percentual points greater than the percentage of votes obtained in the elections;

The Senate is integrated by 128 representatives of the constituent states of the federation. All senators are elected in free universal elections every six years through a parallel voting system as well:

• 64 senators are elected by first-past-the-post plurality, two per state and two for the Federal District elected jointly;
• 32 senators are assigned through the principle of 'first minority', that is, they are awarded to the first runner-up party for each constituent state and the Federal District;
• 32 are elected by proportional representation with open-party lists for which the country conforms a single constituency.

Senators cannot be re-elected for the next immediate term.

Judicial Branch

The judiciary is comprised by the Supreme Court of Justice, comprised by eleven judges or ministers appointed by the President with Senate approval, who interpret laws and judge cases of federal competency. Other institutions of the judiciary are the Electoral Tribunal, collegiate, unitary and district tribunals, and the Council of the Federal Judiciary. The ministers of the Supreme Court will serve for 15 years and cannot be appointed to serve more than once.

State and Local Governments

State Governments

Mexico is a federation of thirty-one free and sovereign states. All constituent states of the federation must have a republican form of government based on a congressional system. The executive power is vested upon a governor elected by first-past-the-post plurality without the possibility of re-election. The legislative power is vested upon a unicameral Congress whose composition is determined by the constitutions of each state, but must include first-past-the-post and proportional representation deputies and they must not be re-elected for the next immediate term. The judiciary is vested upon the tribunals that each state establishes in its constitution. The re-election of the ministers of justice is a prerogative established by each constituent state.

All states are independent and autonomous in their internal administration. The federal government cannot intervene in any particular state's affairs unless there is a full cessation of government powers and through previous study, recommendation and/or approval of the Congress of the Union. The states cannot make an alliance with any foreign power or with any other state. They cannot unilaterally declare war against a foreign nation unless their territory is invaded and cannot wait for the Congress of the Union to issue a declaration of war.

The Federal District

Mexico City does not belong to any state in particular, but to the federation, being the capital of the country and seat of the powers of the Union. As such, it is constituted as a Federal District, ultimately administered by the Powers of the Union. Nonetheless, since the late 1990s certain autonomy and powers have been gradually devolved. The executive power is vested upon a head of government now elected by first-past-the-post plurality. The legislative power is vested upon a unicameral Legislative Assembly. The judicial power is exercised by the Supreme Tribunal of Justice and the Judiciary Council.

The Federal District is divided into delegaciones or boroughs. Though not fully equivalent to a municipality in that they do not have regulatory powers, they have gained limited autonomy in recent years, and the representatives to the head of government are now elected by the citizens as well.

Municipal Governments

All states are divided into municipalities, the smallest autonomous political entity in Mexico. Municipalities are governed through a municipal council (ayuntamiento) headed by a mayor or municipal president (presidente municipal) whose work is supported by a predetermined number of regents (regidores) and trustees (síndicos), according to the constitutions of the states they are part of. Since 1917 there are no intermediate entities or authorities between municipalities and the state governments. Members of the municipal councils cannot be re-elected for the next immediate term. Autonomous municipalities are constitutionally known as 'free municipalities' (municipios libres).

Municipalities are responsible for public services (such as water and sewerage), street lighting, public safety, traffic, supervision of slaughterhouses and the cleaning and maintenance of public parks, gardens and cemeteries, as well as in zoning and urban planning. They may also assist the state and federal governments in education, emergency fire and medical services, environmental protection and maintenance of monuments and historical landmarks. As of 1983, they can collect property taxes and user fees although more funds are obtained from the state and federal governments than from their own collection efforts.