Rep. Diokno pushes for voting threshold based on participating senators

House prosecutor Chel Diokno urged the Senate impeachment court to interpret the constitutional two-thirds voting requirement based on the number of senators legally and factually capable of participating in the trial, rather than automatically using all 24 Senate seats.

In his opening oral arguments, Diokno said the Constitution’s requirement that conviction of Vice President Sara Duterte must be supported by a two-thirds vote remained unchanged, but the court must determine how many senators should constitutionally be included in the computation.

“The Constitution requires two-thirds. The question before this court, is two-thirds of how many,” Diokno said, noting that the four former Supreme Court justices who appeared as amici curiae, or literally friends of the court, had different approaches to interpreting the phrase “all members of the Senate.”

He said all four, however, agreed that 16 votes should not necessarily be treated as an absolute number under every circumstance.

Diokno anchored the prosecution’s argument on the principle of accountability, which he said runs through the 1987 Constitution and is central to the impeachment process.

He cited Article XI, Section 1, which states that public office is a public trust and that public officers must remain accountable to the people.

The lawmaker also stressed that senators sitting as impeachment judges perform an extraordinary constitutional function distinct from ordinary legislative work.

The Constitution requires senators to take an oath or affirmation when sitting as an impeachment court, Diokno said, adding that this is the only instance in which senators are required to take an oath separate from the one they took upon assuming office.

“Paano ito gagawin ng senador na hindi naging hukom dahil hindi naman nakapag-oath,” Diokno said, arguing that a senator who cannot participate as a judge should not automatically be included in the denominator used to determine the two-thirds threshold.

He similarly questioned the inclusion of a senator who was absent from hearings and therefore unable to hear evidence, deliberate and vote.

“Kanino haharap at mananagot ang impeached official kung absent o hindi available ang huwes--sa bakanteng upuan at mesang malamig?” he said.

Diokno cited the Supreme Court’s 1938 ruling in Avelino v. Cuenco, while acknowledging that the case involved a legislative quorum under the 1935 Constitution rather than the two-thirds requirement for impeachment conviction.

He said the case nevertheless demonstrated that constitutional membership provisions could be interpreted in light of the actual circumstances affecting an institution’s ability to perform its functions.

He also addressed the case of Bayan v. Zamora, which has been cited in arguments for maintaining a fixed 16-vote threshold.

According to Diokno, the Supreme Court in that case did not interpret the constitutional voting threshold but merely referred to 16 votes as an arithmetic illustration. He noted that two-thirds of either 23 or 24 senators would amount to 16, meaning the reference did not establish 16 as an immutable constitutional threshold.

Diokno said keeping the denominator fixed at 24 despite senators being legally unable to participate could produce what he described as an “absurd” result. “If the denominator is fixed at 24, conviction would always require 16 votes,” he said.

He argued that such a setup could amount to an acquittal by default because the votes of senators who are incapable of acting as judges would effectively be counted in determining the number needed for conviction.

The prosecution lawyer also rejected arguments that changing the denominator during the trial would amount to changing the rules midway through the proceedings.

“The Constitutional rule has not changed,” Diokno said. “Noong nagsimula ang trial, ngayong tumatakbo ang trial, at maging pagdating sa final vote, two-thirds pa rin ang requirement.”

What the court must decide, he said, is which senators should constitutionally be included in the count based on their actual legal capacity to perform the functions of impeachment judges.

Diokno further argued that changing the denominator should not be characterized simply as lowering the number of votes needed to convict.

Using 20 senators as an example, he said two-thirds would require 14 votes for conviction, while seven votes would be enough to prevent conviction. Under a 24-member denominator, meanwhile, 16 votes would be needed to convict and nine votes would prevent conviction.

“A different denominator does not guarantee conviction. It changes the arithmetic on both sides,” he said.

He said the prosecution would respect whatever threshold the impeachment court ultimately determines.

“If the court determines 16, we present our evidence. If the court determines another number, we present the same evidence,” Diokno said, stressing that the evidence and the prosecution’s burden would remain unchanged regardless of the denominator.

“Because ultimately, two-thirds remains two-thirds,” Diokno said.

The Senate impeachment court on Wednesday overturned its July 6 ruling requiring 16 votes to convict Vice President Sara Duterte, ruling that the two-thirds threshold should instead be computed based on senators who are legally and factually capable of participating in the proceedings.

Thirteen senator-judges voted to overturn the previous ruling: Vicente Sotto III, Juan Miguel Zubiri, Sherwin Gatchalian, Bam Aquino, JV Ejercito, Risa Hontiveros, Lito Lapid, Panfilo Lacson, Francis Pangilinan, Mark Villar, Raffy Tulfo, Erwin Tulfo and Joel Villanueva.

Presiding Officer Francis “Chiz” Escudero voted against the motion.

Escudero said six senator-judges did not participate in the vote: Alan Cayetano, Pia Cayetano, Christopher “Bong” Go, Imee Marcos, Camille Villar and Robin Padilla.

Under the new ruling, the phrase “all members of the Senate” in the constitutional provision requiring a two-thirds concurrence for conviction will refer to senators who, at the time of the vote, remain legally and factually capable of participating in the impeachment proceedings.