Legislative District Creation Population Thresholds and the Limits of Projections

The creation of a new legislative district is not merely a matter of legislative convenience—it must satisfy constitutional population requirements grounded on credible, official data. In Aldaba v. Commission on Elections (G.R. No. 188078, January 25, 2010), the Supreme Court struck down Republic Act No. 9591, which created a separate legislative district for Malolos City, Bulacan. The ruling clarifies when population projections may be used to meet the constitutional threshold of 250,000 inhabitants for city representation.

The Facts

Before 2009, Bulacan had four legislative districts, with Malolos City forming part of the First District together with the municipalities of Hagonoy, Calumpit, Pulilan, Bulacan, and Paombong. On May 1, 2009, RA 9591 lapsed into law, amending Malolos' City Charter to create a separate legislative district for the city.

The legislative bills were filed in 2007 based on an undated certification from a Regional Director of the National Statistics Office (NSO) stating that the projected population of Malolos would be 254,030 by the year 2010, using a population growth rate of 3.78 between 1995 and 2000. Petitioners—taxpayers, registered voters, and residents of Malolos—challenged the law's constitutionality, arguing that the city failed to meet the minimum population requirement.

The Issue

The sole question was whether Malolos City had a population of at least 250,000—whether actual or projected—to justify the creation of its own legislative district in time for the May 10, 2010 elections.

The Ruling

The Supreme Court granted the petition and declared RA 9591 unconstitutional for violating Section 5(3), Article VI of the 1987 Constitution, which requires each city to have a population of at least two hundred fifty thousand to merit at least one representative.

The Court found the NSO certification legally defective on several grounds. First, under Executive Order No. 135 (1993), certifications based on demographic projections may only be issued if such projections are declared official by the National Statistics Coordination Board (NSCB). Second, only the NSO Administrator or a designated certifying officer may issue such certifications—the Regional Director had no authority. Third, intercensal population projections must be as of the middle of every year, a requirement the undated certification failed to meet.

The projection was also internally inconsistent. Using the certification's own growth rate of 3.78% per year, the Court calculated that Malolos' population of 175,291 in 2000 would grow to only 241,550 by 2010—well below the 250,000 threshold. Even using the 2007 Census figure of 223,069, the population would reach only about 248,365 by August 2010.

The Court rejected the argument that Congress' choice of standards was non-justiciable. Questions involving compliance with constitutional standards fall within the Court's checking function under the Constitution. As the Court noted, district apportionment laws are subject to review by the courts, citing Macias v. Commission on Elections.

The Ordinance appended to the 1987 Constitution provides that a city whose population increases to more than 250,000 becomes entitled to at least one Member in the election immediately following such attainment. Since there was no official record that Malolos had attained or would attain the threshold before the May 2010 elections, the city was not qualified for its own district.

Practical Takeaways

• Population projections must come from official, credible sources. Certifications based on demographic projections require NSCB declaration of official status and issuance by the NSO Administrator or a designated officer.
• The 250,000 population threshold is a hard constitutional requirement. Congress cannot rely on speculative or internally inconsistent projections to create a legislative district for a city.
• Timing matters. A city becomes entitled to a district only in the election immediately following its attainment of the 250,000 population.
• Courts will review legislative apportionment. The constitutionality of district creation laws is justiciable, not a political question immune from judicial scrutiny.
• Provinces are treated differently. Unlike cities, each province is entitled to at least one representative regardless of population size.

This article is general information and not legal advice. For your specific situation, consult a lawyer or ask ASG Legal AI.