Former Senate President Franklin Drilon on Sunday dismissed what he claimed was Senator Alan Cayetano’s unfounded claim that changing the conviction threshold needed to convict Vice President Sara Duterte mid-trial could render the entire proceedings void, arguing that past rulings could always be reviewed by senator-judges if warranted. 

Cayetano, a Duterte ally, maintained that questions over the threshold had already been settled by Presiding Officer Chiz Escudero as early as 6 July — the onset of the trial — rendering any revisit by the Senate impeachment court unnecessary.

Drilon countered, however, that Escudero deliberately did not structure his ruling as final to anticipate potential legal challenges and allow the Supreme Court to weigh in on the issue, given the absence of several senator-judges.

“A mistrial? That’s incorrect. First of all, Senator Escudero’s ruling can be appealed to the impeachment court — to the 24 senators, or however many there are — who constitute that court. That’s why his ruling is not set in stone,” the erstwhile Senate leader said in Filipino in a radio interview.

“In fact, he acknowledges that an appeal can be made to the Supreme Court en banc; therefore, the claim of a mistrial is baseless,” he added. 

Beyond rules change

Drilon pointed out that the threshold issue goes beyond a mere attempt to alter the rules midway through the trial. Instead, it centers on a dispute over a constitutional provision that the Senate, which retains authority to interpret its own rules, ultimately has the power to resolve.

Cayetano has opposed efforts to review Escudero’s 6 July ruling as it would effectively lower the conviction threshold needed to find Duterte guilty of the impeachable offenses leveled against her, which could derail her presidential ambition in 2028. 

In that decision, Escudero upheld the constitutional requirement that two-thirds of the full 24-member Senate, equivalent to 16 votes, is needed to convict an impeached official, even if four of their colleagues are absent from the trial. 

In a Facebook live on Friday, Cayetano argued that fairness dictates abiding by the established rules of the impeachment court from beginning to end, warning that altering them as the proceedings progressed could trigger a mistrial and risk rendering the proceedings void from the outset. 

With Senators Jinggoy Estrada, Rodante Marcoleta, Bato dela Rosa, and Loren Legarda unable to attend the trial due to their legal battles, Senator Erwin Tulfo previously warned that insisting on a voting threshold of 24 will result in an “acquittal by default,” regardless of how the evidence is presented.

Fairness in doubt

This, he said, also compromises the fairness of the proceedings.

Cayetano issued the warning days before the impeachment court hands down the decision on whether to retain Escudero’s ruling scheduled for 23 September.

Before that, the impeachment court heard the positions of retired Supreme Court chief justices Hilario Davide Jr., Artemio Panganiban, and Reynato Puno, and associate justice Adolfo Azcuna, whom it tapped as amici curiae (friends of the court). 

Their legal advice would shape the court’s decision on how to lawfully interpret Article XI, Section 3(6) of the 1987 Constitution, the provision that sets the conviction threshold, to prevent a possible deadlock on the day of judgment against Duterte, tentatively set for December. 

Of the four magistrates, only Azcuna maintained that the denominator for computing the two-thirds should remain at 24 sitting senators as long as they hold office.