On Wednesday, Sept. 23, 2026, the Senate impeachment court voted 13-1 to lower the baseline number of votes required to either convict or acquit Vice President Sara Duterte from 16 to 14 by excluding senators who are unable to attend and participate in the impeachment proceedings.
The 13 senator-judges voted in favor, with Presiding Officer Francis “Chiz” Escudero casting the lone dissenting vote, while Senators Alan Peter Cayetano, Pia Cayetano, Imee Marcos, Christopher “Bong” Go, Camille Villar and Robin Padilla did not participate.
The Senate impeachment court has now adopted a rule that the two-thirds denominator should consist of senators who are legally and factually capable of participating in the impeachment trial.
The impeachment court simply redefined “all members of the Senate” to mean only those legally and factually capable of participating, excluding the four absent or incapacitated members and setting the active denominator at 20, making two-thirds 13.33, which rounds up to 14 votes.
Presiding Officer Escudero, in a statement, said he would enforce the ruling as the controlling judgment until the Supreme Court (SC) says otherwise.
A group of law school deans, professors and private practitioners stated in a press conference that the ruling was a “sound upholding of the two-thirds requirement” aligned with the 1987 Constitution.
However, both critics and supporters of VP Duterte filed petitions with the SC challenging the impeachment court’s ruling. Former executive secretary Victor Rodriguez argued that the Senate unlawfully rewrote the Constitution, while lawyer Ernesto Francisco Jr. claimed the Senate acted with grave abuse of discretion.
The Senate’s interpretation has a practical and logical basis. Indeed, when a senator is legally incapable of functioning as an impeachment judge because they are detained, suspended, medically incapacitated, or otherwise unable to participate, that senator should not be included in the denominator for a vote requiring two-thirds of the Senate’s members under the Constitution.
In other words, the Senate impeachment court’s new ruling on voting means that the two-thirds threshold shall be based only on those who can participate in the proceedings. With four senators unable to participate, the baseline is now 20; hence, 14 votes — not 16 — are required to convict or acquit VP Duterte.
The House prosecution has also argued that the denominator should not automatically be 24.
But VP Duterte’s camp has an equally serious textual argument. The Constitution says conviction requires the concurrence of two-thirds of “all the Members of the Senate.” This phrase could naturally be understood as referring to the full 24-member Senate, rather than whoever happens to be participating at the time. Paolo Duterte has already raised exactly this objection.
As the final arbiter on constitutional and legal issues, the SC’s ruling on this matter could settle it and be beneficial to all. The worst outcome would be for the Senate to convict or acquit Sara Duterte and only afterward have the country fight over whether the required number of votes was correctly calculated.
This would cause a bigger constitutional controversy. A SC determination could establish a clear rule before the final judgment. That would make the eventual result considerably more defensible, regardless of whether one supports or opposes the vice president.
There is also an important precedent for the Court examining legal questions surrounding impeachment. The SC, in its 2025 ruling involving the earlier impeachment proceedings against the vice president, expressly held that legal issues involving impeachment proceedings can be subject to judicial review.
But there is a significant distinction here, since the Constitution gives the Senate the “sole power to try and decide” impeachment cases. The question now is: does that power include changing the baseline in voting? The stronger argument for judicial review is certainly for the SC to determine the constitutional rules governing the Senate’s exercise of that power.
In abandoning the earlier fixed 16 votes needed to convict or acquit, the Senate’s action could not simply be described as “deciding based on those present.” That is broader than what the Senate actually decided. The new rule is more specific: the denominator excludes senators who are legally or factually unable to participate, rather than simply excluding an ordinary senator because he or she happens to be absent.
That distinction could be very important before the SC. I think the strongest resolution would be for the constitutional issue to be settled before the final conviction vote, if the Court determines that it has jurisdiction over this issue. It would remove much of the uncertainty over the arithmetic and allow the impeachment trial to focus on the substantive question: is there sufficient evidence to convict or not?
Former SC chief justices Artemio Panganiban, Reynato Puno and Hilario Davide, Jr., along with retired associate SC justice Adolfo Azcuna, acting as amici curiae (friends of the court), provided the senator-judges their respective views on the constitutional interpretation of the two-thirds voting threshold needed to convict or acquit the impeached VP Duterte.
The interesting question now is whether the SC will actually take jurisdiction over the challenge to the Senate’s interpretation. If it does, we will have to wait for the Honorable SC’s interpretation and ruling. That may ultimately be the decisive constitutional issue.