Future impeachment courts can decide differently in threshold question

The Senate impeachment court votes on the threshold required to convict an impeachable official on Sept. 23, 2026, with 13 senator-judges voting in favor and one against.

Senate of the Philippines / Joseph Vidal via Facebook

MANILA, Philippines — Future impeachment courts can compute the two-thirds vote for conviction differently from the court trying Vice President Sara Duterte, which ruled this week that only senators able to take part in the trial will be counted.

Senator-judges voted 13-1 on Wednesday, September 23, to overturn presiding officer Sen. Chiz Escudero's July 6 ruling that conviction required exactly 16 votes, or two-thirds of all 24 senators. 

Under the new ruling, the impeachment court will still follow the two-thirds threshold, but with a criteria that limits "all members of the Senate" to those who can actually participate at the time of the vote.  

With four senators currently not taking part in the trial — namely Sens. Bato dela Rosa, Jinggoy Estrada, Loren Legarda and Rodante Marcoleta — the number of senators that form the denominator is 20.   

Escudero yesterday expressly stated that the new count applies pro hac vice, or for this occasion only, so it sets no binding precedent for later impeachment trials.

House prosecutor Rep. Chel Diokno (Akbayan) said at a briefing Thursday, September 24, that the courts use the term "just to stress that it applies only here and cannot be used for future possible impeachment proceedings."

Diokno contrasted the ruling yesterday with decisions of the Supreme Court, which can be applied to similar cases in the future. 

That principle, called stare decisis, binds lower courts to follow the high court's rulings.  

Impeachment court rulings do not work that way, Diokno said. 

"Hindi natin mahihintulad iyon doon nga sa judicial precedent o stare decisis (We cannot liken it to judicial precedent or stare decisis)," he said. 

An impeachment court is not part of the judiciary as it is composed of the members of the Senate, which the 1987 Constitution gives the sole power to try and decide impeachment cases.  

One of the defense's main arguments against dropping the 16-vote threshold yesterday was that it would set a dangerous precedent for other provisions that require a two-thirds vote from the Senate. 

Defense counsel Michael Poa yesterday argued there would be potential impacts on the thresholds for extending or revoking martial law, or expelling a member of the Senate, among others. 

However, Diokno, during the oral arguments, urged the court to hew to its mandate of upholding an "accountability Constitution" and to avoid the "absurdity" of requiring 16 votes no matter the actual number of senators present.  

Escudero, in delivering the court ruling yesterday, stressed that because it is a procedural ruling rather than a formal amendment to the rules, it is not binding and has merely a persuasive effect on future tribunals.

Escudero was the lone dissenter in the vote, which was expected given it was his ruling that was being overturned. 

The court's ruling was made under "extraordinary" and "unprecedented" circumstances, Escudero said.

"The chair hopes that it shall never happen again," he said. 

Three out of four retired justices who advised the court urged it to adopt a "functional" reading of the Constitution. As explained by former Chief Justice Reynato Puno, because the framers purposefully used a fraction ("two-thirds") rather than explicitly writing out the number "16," the voting base is meant to be flexible and exclude non-participating senators.