OPINION
Senate facing constitutional standoff
Legal analysts and political figures have warned that if the Senate actively defies a future Supreme Court ruling or TRO, it would trigger a full-blown constitutional crisis and a deep institutional stalemate between the legislative and judicial branches.
Senate President Sherwin Gatchalian, like the captain of a ship, is charting the Philippine Senate into the high seas of many questions, queries by lawyers, analysts, legal experts, civil society groups mumbling and asking why, with uncertainty, and now facing a major constitutional standoff following the Senate impeachment court’s contentious 23 September ruling.
The Senate court voted to abandon the traditional fixed 16-vote conviction threshold (representing a strict two-thirds of all 24 senators) for the impeachment trial of Vice President Sara Duterte. Instead, the newly adopted “functional rule” bases the two-thirds requirement on the number of senator-judges who are legally and factually capable of participating when judgment is rendered.
The core of dispute
1. The New “Functional Rule”: The new threshold excludes members who are unable to participate (due to factors such as legal disqualification, absence, and law enforcement issues). This dynamically lowers the mathematical number required to secure an impeachment conviction.
2. The Legal Challenge: On 24 September 2026, a formal petition was filed with the Supreme Court seeking to nullify the Senate’s newly adopted rule. Opponents argued that redefining the constitutional voting threshold through an internal chamber rule violated the text of the 1987 Constitution which explicitly bases the voting fraction on the total membership of the body.
Current status and fallout
Despite the escalating legal battle at the Supreme Court, Senate President Gatchalian stated on 25 September that the impeachment trial will continue under the flexible voting framework unless the High Court explicitly issues a Temporary Restraining Order (TRO).
Legal analysts and political figures have warned that if the Senate actively defies a future Supreme Court ruling or TRO, it would trigger a full-blown constitutional crisis and a deep institutional stalemate between the legislative and judicial branches.
When and where the storm started
The political debate surrounding the “constitutional 16” threshold highlights the deep structural and legal disagreements in Philippine governance, particularly in the ongoing impeachment trial of Vice President Sara Duterte.
Supporters and critics of the recent threshold adjustment view its legal validity and potential fallout differently.
1. The Legal Battle Over the Denominator
The controversy centers on whether the 1987 Constitution prescribes a fixed or a functional denominator for an impeachment conviction.
a) The Traditional (Fixed View): Legal experts and defense lawyers argue that Article XI, Section 3(6) of the Constitution mandates the concurrence of two-thirds of all members of the Senate (which is 16 votes in a 24-member chamber). Altering this threshold midway through a trial is criticized as a violation of procedural due process and an act of extra-constitutional judicial or legislative legislation.
b) The Adjusted (Functional) View: On 23 September 2026, the Senate, sitting as an impeachment court, voted 13-1 to adopt a new interpretation. This rule excludes senators who are legally or factually incapable of participating (such as those suspended or detained), effectively lowering the required vote to 14 based on 20 participating senator-judges.
Proponents argued the two-thirds