G.R. No. L-44640 - Sanidad vs. Commission on Elections

On September 2, 1976, President Marcos promulgated Presidential Decree No. 991 calling a national referendum on October 16, 1976 to resolve: continuation of martial law; convening or replacement of the interim National Assembly; duration of its existence; and the period of the President’s special powers.
On September 22, 1976, Presidential Decree No. 1031 amended PD 991 by adopting the voting and canvass rules for barangays and repealing Section 4 of PD 991. On the same day, PD 1033 stated the nine questions to be submitted in the referendum-plebiscite, including proposed constitutional amendments.

L-44640: Pablo C. Sanidad and Pablito V. Sanidad sought prohibition and preliminary injunction to enjoin PD 991, 1031, and 1033, arguing that the President lacks constituent power under the 1935 and 1973 Constitutions and that the scheduled referendum-plebiscite has no legal basis.
L-44684 and L-44714: Vicente M. Guzman and Raul M. Gonzales et al. filed similar petitions for prohibition with preliminary injunction, contending that only the interim National Assembly may propose amendments; that the short notice invalidates the plebiscite; and that lowering the voting age to 15–17 alters the Constitution.

The Solicitor General, for the Commission on Elections, argued lack of locus standi, political-nature of the issue, the President’s exclusive constituent power during transition, and normalization purposes of the plebiscite.
Oral arguments were heard October 7–8, 1976. The Supreme Court, en banc, deliberated whether (a) the challenges are justiciable and (b) the President has authority to propose amendments and call the referendum-plebiscite.

On March 14, 1977, the Supreme Court, by an 8–2 vote, dismissed all three petitions, holding the issues justiciable, the President’s actions valid as indirect exercise of the people’s constituent power, and the submission to the people sufficient.
Three Justices filed separate concurring opinions; two Justices (Teehankee and Munoz Palma) dissented, arguing lack of presidential constituent power and procedural defects in the submission.

Are the petitions challenging the constitutionality of Presidential Decrees Nos. 991, 1031, and 1033 justiciable or political questions beyond judicial review?
During the transition without a convened interim National Assembly, does the incumbent President have the power to propose constitutional amendments and prescribe the referendum-plebiscite machinery?
Was the submission of the proposed amendments to the people on October 16, 1976 sufficiently and properly made, given the notice and the plebiscite procedures (including participation of 15–17-year-olds)?