The current Senate deadlock, where the Senate President and the Senate President Pro Tempore are on opposing sides, sees no clear resolution if the current numbers hold and neither faction yields.

A legal expert said the doctrine of a living Constitution cuts both ways, making it difficult to unseat Senate President Cayetano despite the shift in the majority following Chiz Escudero’s transfer to the camp of Senate President Pro Tempore Win Gatchalian.

Former University of the East College of Law dean Amado Valdez noted that the Gatchalian bloc limited its move to securing the Senate President Pro Tempore seat and did not attempt to seize the chamber’s top post. However, he said, the realignment could eventually weaken Cayetano’s grip on the Senate leadership.

If the dispute reaches the Supreme Court (SC), the living Constitution argument would likely apply, according to Valdez.

“The SC does not decide in a vacuum; it looks at the facts, the prevailing public mood, treating it as a question of law, or even declines by treating it as a political question,” he said.

Based on the doctrine, senators switching sides is not an “intervening event” in the legal sense but a political act that has political remedies, through a formal vote to remove the Senate President, conducted with a proper, uncontested quorum.

Gatchalian’s 12 senators remain a disputed quorum, which he cannot invoke to effect a leadership change by citing constitutional flexibility.

The faction supporting Gatchalian, backed by the Palace, had invoked the Supreme Court’s landmark 1949 Avelino v. Cuenco ruling on a Senate quorum.

In the decision, the core issue was not merely numerical, as the Senate President Jose Avelino was at the center of corruption allegations, and his leadership was in question due to integrity concerns.

The quorum battle was then almost incidental to the deeper question of whether a tainted leadership could shield itself through procedural entrenchment.

Cayetano argues that the circumstances are materially different. His bloc argues that the Gatchalian maneuver is procedurally questionable and not the existing leadership.

The attempt to install a rival Pro Tempore with a disputed quorum is the aberration, not the status quo being defended.

The Court in Avelino also ultimately declined to intervene on political-question grounds in its first ruling, before reversing course.

Such an oscillation showed that the SC reserves the right to recalibrate whether a Senate dispute is justiciable or a purely internal political question, depending on how broadly the constitutional stakes are involved.

The final arbiter, according to the legal expert, would still be the numbers. Legal arguments establish legitimacy, but floor votes establish reality.

Valdez said that while the numbers will ultimately settle the dispute, Cayetano remains on solid legal ground in maintaining his hold on the Senate presidency.

Should the issue reach the Supreme Court, the High Tribunal would likely weigh three questions: who effectively controls the Senate floor; what serves the public interest; and whether judicial intervention would heal or deepen the institution’s divisions.

On all three fronts, the Cayetano bloc currently has the stronger argument, provided it maintains its numbers.