4th federal electoral district of Tamaulipas

Tamaulipas's districts in 2017–2022

The 4th federal electoral district of Tamaulipas (Spanish: Distrito electoral federal 04 de Tamaulipas) is one of the 300 electoral districts into which Mexico is divided for elections to the federal Chamber of Deputies and one of eight such districts in the state of Tamaulipas.

It elects one deputy to the lower house of Congress for each three-year legislative session by means of the first-past-the-post system. Votes cast in the district also count towards the calculation of proportional representation ("plurinominal") deputies elected from the second region.

The current member for the district, elected in the 2024 general election, is Mario Alberto López Hernández. Originally elected for the National Regeneration Movement (Morena), he switched to the Ecologist Green Party of Mexico (PVEM) at the start of the congressional session.

Tamaulipas lost a district in the 2023 districting plan adopted by the National Electoral Institute (INE), which is to be used for the 2024, 2027 and 2030 federal elections, but the 4th district was largely unaffected. It is located in the north of the state and comprises 197 electoral precincts (secciones electorales) in the urban core of the municipality of Matamoros.

The head town (cabecera distrital), where results from individual polling stations are gathered together and tallied, is the city of Matamoros. The district reported a population of 439,075 in the 2020 Census.

2017–2022

Between 2017 and 2022, Tamaulipas accounted for nine single-member congressional seats. The 4th district's head town was at Matamoros and it covered 157 precincts in the municipality's urban core.

2005–2017

Under the 2005 plan, Tamaulipas had eight districts. This district's head town was at Matamoros and it covered 173 precincts in the municipality's urban core.

1996–2005

In the 1996 scheme, under which Tamaulipas lost a single-member seat, the district had its head town at Matamoros and it covered the whole of the city and its municipality.

1978–1996

The districting scheme in force from 1978 to 1996 was the result of the 1977 electoral reforms, which increased the number of single-member seats in the Chamber of Deputies from 196 to 300. Under that plan, Tamaulipas's seat allocation rose from six to nine. The 4th district's head town was at the state capital, Ciudad Victoria, and it covered six municipalities in that part of the state: Bustamante, Jaumave, Miquihuana, Palmillas, Tula and Victoria.