Impeachment constitutes one of the gravest and most consequential powers accorded by the Philippine Constitution, serving as a vital mechanism to ensure accountability among the highest officials of the land. The framers of the 1987 Constitution sought to establish this proceeding as a delicate equilibrium: a defense against the abuse of power, yet carefully constructed so as not to become a mere instrument for partisan manipulation. Its history, however, compels this question: has impeachment, as contemplated by the fundamental law, been executed in accordance with its intended purpose?

Estrada’s Impeachment: A Process Interrupted

The impeachment of President Joseph Estrada in 2000 marked the nation’s first significant test of the impeachment process. The House voted 92-41 to impeach, surpassing the required threshold. However, the Senate trial was cut short when the senators voted 11-10 not to open an envelope believed to hold key evidence, triggering mass protests and eventually Estrada’s resignation.

This episode left crucial questions unresolved: What happens when the impeachment process collides with an overwhelming popular movement? Does a resignation amid the proceedings fulfill the constitutional requirement? The Estrada experience showed the vulnerabilities of impeachment when due process is disrupted, and political pressure overtakes institutional mechanisms.

Corona’s Impeachment: Compromised Institutions

The 2011–2012 impeachment and conviction of Chief Justice Renato Corona stands as the most controversial proceeding to date. Several impeachment articles were dropped due to weak evidence, and Corona’s waiver of bank secrecy was made under duress, undermining the principle of voluntary disclosure. However, the crucial evidence that led to Corona’s conviction was his own testimony regarding undisclosed foreign currency deposits not listed in his SALN.

There was also the subsequent revelation that 20 senators received a combined P1.107 billion in additional Priority Development Assistance Fund “pork barrel” allocations mere months after they voted to convict. Corona’s defense had prior disclosures suggesting an orchestrated plan to offer P100 million per senator for a conviction vote.

Moreover, the Napoles scandal revealed that much of these funds were later misused, further eroding the public trust and implicating members of the Senate in a broader web of corruption. Even with the 20-3 conviction vote, the presence of such inducements rendered the outcome suspect.

Sereno v The Supreme Court : An Exception to Impeachment?

In 2018, while impeachment proceedings had been initiated in the House, the Supreme Court intervened by granting the quo warranto petition filed by Solicitor General Jose Calida to void Chief Justice Lourdes Sereno’s appointment, on the grounds that it was null from the outset for her failure to regularly file her SALN while a member of the UP faculty. This action bypassed the exclusive impeachment process provided for constitutional officers, introducing a critical precedent: that the judiciary could remove one of its own through means other than impeachment.

Duterte Impeachment: House v. Senate

The impeachment proceedings against Vice President Sara Duterte, initiated in February 2025, followed a more rigorous approach. The House charged Duterte with misuse of funds, unexplained wealth, and betrayal of public trust, supported by significant documentary evidence.

Congressional investigators unearthed questionable disbursements, including P612.50 million in confidential funds, and flagged irregularities in acknowledgement receipts amounting to P23.8 million. Interestingly, the complaint contains articles that were gathered through valid legislative oversight, avoiding the prosecution pitfalls that plagued earlier impeachments.

However, the process is currently stalled with the battle for the presidency of the Senate in the 20th Congress at stake. Pro-Duterte senators have shown a preference for a candidate that will agree to the immediate dismissal of the complaint without hearing the evidence.

In this sense, the Sara Duterte impeachment serves as a test: Will the Senate, as an impeachment court, resolve to dismiss the complaint without the presentation of evidence? Is this constitutionally valid and sound in a democratic system?

Impeachment remains one of the Philippines’ most consequential constitutional checks on power. Its history is a powerful reminder of both the promise and peril inherent in the process: promise, when conducted with rigor and fairness; peril, when subverted for political gain or corrupted by extralegal pressures.

As the Sara Duterte impeachment trial unfolds, the challenge for lawmakers and the nation is to reaffirm a commitment to accountability, transparency, and institutional integrity—the very values the 1987 Constitution was crafted to protect.