Retired chief justices on Wednesday challenged the Senate’s 16-vote threshold for convicting Vice President Sara Duterte, arguing that the Constitution’s two-thirds requirement cannot be reduced to fixed arithmetic when some senators may be unable to perform their duties as impeachment judges.

Former Chief Justices Reynato Puno and Artemio Panganiban, who appeared before the impeachment court, and former Chief Justice Hilario Davide Jr., whose memorandum was read to the senator-judges, differed in their reasoning but converged on the meaning of the phrase “two-thirds of all the Members of the Senate.”

Their submissions came as the Senate reconsiders whether the Constitution requires two-thirds of the full 24-member Senate, 16 votes, or two-thirds of the senators legally and functionally able to participate in the impeachment trial.

At stake is whether a senator who is legally unable, physically unable or has not meaningfully participated in the proceedings should nevertheless be counted in determining the number of votes needed to convict.

Who are the ‘members’?

Davide addressed that question by starting with the Constitution’s choice of the word “members.” A delegate to the 1971 Constitutional Convention and member of the 1986 Constitutional Commission, Davide said there was no debate on the issue while drafting the 1973 and 1987 Constitutions.

He said it was presumed that “members” referred to living senators capable of exercising their powers and performing their duties, and not those prevented from doing so by physical or legal restraints.

“This is the spirit of the provision. It could not be otherwise. Any interpretation to the contrary would defy reason, logic and common sense; tolerate an absurdity; and perpetuate an injustice,” Davide said.

“Accordingly, a Senator-Judge who did not attend any session of the Court for any reason whatsoever or who never acted or performed the duties as a Senator-Judge must be deemed to have never participated in the performance of the duties as such,” he said.

Reality changes denominator

Panganiban similarly rejected treating the two-thirds requirement as an abstract calculation of 16 out of 24. “Read literally, it is 16 of 24, but only ‘in the abstract. Reality, sometimes, changes the denominator in mathematics,’” Panganiban said.

He claimed a senator who has not meaningfully participated in the proceedings should not be allowed to vote on Duterte’s fate. Truth in an impeachment trial, Panganiban said, comes from examining evidence and hearing witnesses testify, including their “body language, tone of voice, and spontaneity.”

He invoked the ancient Greek statesman Themistocles: “Strike me as you may, but hear me first.”

Panganiban contrasted those “sweating it out” in the session hall with absent senators who may be sightseeing abroad or otherwise away from the proceedings.

That emphasis on actual participation led back to the arithmetic at the heart of the dispute: if the number of senators who can meaningfully function as impeachment judges changes, does the two-thirds calculation necessarily remain fixed?

No exact number found

Puno, meanwhile, answered that question by challenging the premise that the Constitution intended to establish an immutable number of votes.

“If it is a fixed number, then the Constitution should have simply stated that the number of votes to convict is 16, period. By using two-thirds, the number of votes to convict will have to move depending on certain factors,” he said.

A conviction in an impeachment case could be annulled if political forces deliberately prevent senator-judges from participating and thereby deprive the respondent of a fair and constitutionally proper trial, retired Chief Justice Reynato Puno told the Senate impeachment court Wednesday.