SOMETHING almost surreal is unfolding in the constitutional debate over the impeachment trial of Vice President Sara Duterte.
The Constitution appears, at first reading, remarkably uncomplicated. Article XI, Section 3(6) says: “No person shall be convicted without the concurrence of two-thirds of all the Members of the Senate.” Article VI, meanwhile, says that the Senate shall be composed of 24 senators. Twenty-four multiplied by two-thirds equals 16. No advanced mathematics. No quantum mechanics. No need for a constitutional calculator.
And yet three former Supreme Court chief justices — Hilario Davide Jr., Artemio Panganiban and Reynato Puno — have told the Senate impeachment court that the number need not necessarily remain 16. Retired Associate Justice Adolfo Azcuna disagrees. For him, the constitutional starting point is refreshingly simple: “All means all.” As long as someone remains legally a senator, Azcuna argues, that senator remains part of the denominator, whether detained, ill, abroad, suspended or otherwise unable to participate.
Hence the uncomfortable question: Are three distinguished former Supreme Court chief justices illuminating the Constitution or stretching it precisely when the political consequences of stretching it are greatest?
That question deserves to be asked without questioning anyone’s integrity. Constitutional interpretation is not arithmetic alone. But neither should constitutional arithmetic mysteriously become elastic simply because politics has made the original number inconvenient.
Textual problem
Davide, Panganiban and Puno do not make identical arguments. Davide says the denominator should consist of senators legally and physically qualified to vote. Panganiban emphasizes meaningful participation, truth and fairness in adjudication. Puno prefers what he calls a contextual and functional interpretation, arguing that the framers used a fraction — two-thirds — rather than permanently writing “16” into the Constitution.
These are intellectually defensible interpretive approaches. But there is an inconvenient textual obstacle: the Constitution does not say two-thirds of the senators present, two-thirds of those voting, or two-thirds of those physically capable of attending. It says two-thirds of all the Members of the Senate. I think the word ”all” was not accidentally dropped into the sentence by an inattentive typist.
The same Constitution uses “all the Members” elsewhere when deliberately establishing heightened voting requirements — for treaty concurrence, suspension or expulsion of legislators and other extraordinary constitutional acts. Supreme Court jurisprudence in Bayan v. Zamora has repeatedly treated that language as a genuine constitutional supermajority requirement. That does not automatically decide the current voting-impeachment issue. But it makes the textual problem impossible to wave away.
Precedent
Where exactly is the precedent? This is where the flexible-denominator proposition encounters its greatest difficulty. The most frequently discussed case is Avelino v. Cuenco, the 1949 Senate presidency controversy. But Avelino concerned the existence of a quorum, not the number constitutionally necessary to convict an impeached official. Puno himself expressly acknowledged that Avelino is not the “perfect precedent,” and other retired justices likewise recognized that it does not directly govern the present question.
So, is there a precedent Supreme Court decision squarely holding that senators who remain members of the Senate may be subtracted from the denominator in an impeachment conviction because they are detained, abroad, medically unavailable, hiding, suspended or physically absent? There is analogy. There is constitutional theory. There is functional reasoning. But direct precedent? Thus far, none has been identified.
Rather, Philippine impeachment history provides an awkward counterpoint. Before the 2012 impeachment trial of the late Chief Justice Renato Corona, then-Senate President Juan Ponce Enrile was specifically asked whether the constitutional number would decrease if the Senate itself had fewer members. His answer was emphatic: 16 remained necessary. Asked whether that remained true even with only 20 or 17 senators, Enrile again said 16. That was not a Supreme Court judgment and therefore is not binding constitutional doctrine. But it unquestionably forms part of Senate impeachment history and practice. Corona was eventually convicted by 20 of the 23 senators then voting, comfortably exceeding 16.
Denominator
Another important question is: What neutral principle determines who disappears from the denominator? Detention? Suspension? Medical leave? Being abroad? Failure to attend a certain percentage of trial days? Inability to observe witnesses? Refusal to appear? What happens if a senator participates remotely? What happens when an unavailable senator returns shortly before judgment?
Unless the Senate creates an exceptionally clear and politically neutral rule, a flexible denominator could generate a constitutional temptation far beyond Sara Duterte. Manipulate participation, and you potentially manipulate the number required for conviction.
2028
No one should pretend this constitutional debate exists inside a political vacuum. The Marcos-Duterte alliance that swept the 2022 elections has fractured into an extraordinary political confrontation, and Sara Duterte’s impeachment now intersects directly with the political landscape preceding 2028. The impeachment trial of Sara Duterte is seen as having major implications for the next presidential election.
The numbers help explain why. A Pulse Asia survey conducted from late June to early July 2026 among 2,400 Filipino adults found 49 percent choosing Sara Duterte in one hypothetical six-candidate presidential scenario, against 26 percent for Leni Robredo and 14 percent for Raffy Tulfo. It was an early preference survey, not an election forecast, and preferences can change dramatically before May 2028. But it demonstrates why the impeachment trial of Sara Duterte cannot be separated politically from 2028.
A conviction would remove Duterte from the vice presidency, and Philippine constitutional doctrine recognizes disqualification from future public office as an impeachment penalty; in the Corona case, the Senate’s judgment expressly imposed both removal and disqualification. Whether and how the impeachment court pronounces that sanction in a Duterte judgment would therefore have obvious consequences for her legal ability to seek the presidency in 2028.
An acquittal, conversely, would leave her politically eligible unless some independent legal proceeding produced a separate disqualification.
However, the real issue is bigger than Sara Duterte. The Constitution must survive the politicians currently operating under it. Davide, Panganiban and Puno have offered serious arguments about preventing constitutional paralysis. Azcuna has offered an equally serious warning about transforming a deliberately high supermajority into a moving target. Notably, Davide and Azcuna were both members of the 1986 Constitutional Commission, and Davide himself acknowledged that the framers did not specifically debate this precise denominator problem.
So perhaps the most curious question is not whether three retired chief justices can outvote one retired justice. Constitutional meaning is not decided 3-1 among invited amici. The question is whether ”all the Members” can now acquire a qualification the text itself never expressly supplies: “all the Members — except those whom the Senate decides cannot presently function.” Filipinos should never forget that the 1987 Constitution was built, in no small part, as scar tissue over the wound of one-man rule, the Marcos Sr. dictatorship; its supermajority requirements are meant to be inconvenient by design. An impeachment court that treats “inconvenient” as synonymous with “flexible” sets a precedent far more dangerous.
Filipinos should take note that the Constitution should govern politics. The politics should never be allowed to redefine the Constitution merely because the original arithmetic has become politically inconvenient and uncomfortable.
