By: Tita C. ValderamaThe Philippine Senate, sitting as an impeachment court, opened Vice President Sara Duterte’s impeachment trial on Monday in what could become the country’s most consequential constitutional proceeding since the conviction of former Chief Justice Renato Corona in 2012. The stakes extend far beyond Duterte’s political survival, testing not only the allegations against the country’s second-highest official but the resilience of Philippine democratic institutions and their ability to function independently amid deep political polarization.The proceedings offer a familiar question confronting many Asian democracies: Can constitutional institutions remain credible when legal accountability and political rivalry become inseparable?Duterte faces charges of betrayal of public trust, culpable violation of the Constitution, misuse of P612.5 million (US$9.98 million) in confidential funds, concealing unexplained wealth, bribery involving Department of Education officials, and public threats against President Ferdinand Marcos Jr., first lady Liza Araneta-Marcos and former House Speaker Martin Romualdez. She has denied all allegations and dismissed these as politically motivated.2028 stakesThe outcome could fundamentally reshape the Philippines’ political landscape ahead of the 2028 presidential election, where Duterte remains one of the strongest prospective candidates. A conviction would remove her from office and could permanently disqualify her from holding public office, eliminating the administration’s most formidable rival in the next presidential race. An acquittal could be equally transformative. Duterte would likely emerge politically strengthened, reinforcing her claim that the impeachment was driven more by politics than evidence and casting the Marcos administration as unable to stop its principal challenger despite commanding the machinery of government.For Marcos, therefore, the trial presents risks regardless of its outcome. His administration cannot afford to appear as though it is weaponizing impeachment against a political opponent, yet neither can it ignore serious allegations involving one of the country’s highest officials.The Senate, meanwhile, carries perhaps the greatest burden. Its legitimacy will rest not on whether Duterte is convicted or acquitted but on whether Filipinos believe the verdict was reached fairly and strictly according to law.Setting the rulesThe first day of proceedings reflected both the strengths and vulnerabilities of the process. Senators spent more than an hour debating whether Senate President Sherwin Gatchalian or Sen. Francis Escudero should preside over the proceedings before electing Escudero, 12-8, despite strong objections from the minority led by Sen. Alan Peter Cayetano, who was ousted on June 3 as Senate president and subsequently replaced by Gatchalian.Escudero then settled key procedural issues, including affirming that conviction requires at least 16 votes—the constitutional two-thirds threshold—and that the House prosecution bears the burden of proving its case through clear and convincing evidence.Those decisions may appear technical, but they establish the legal framework that will govern the months-long trial and reduce uncertainty over procedural disputes that could otherwise undermine the proceedings.Competing narrativesThe opening statements likewise presented two sharply contrasting visions of the case.Chief prosecutor Gerville Luistro urged senators to set politics aside and judge only the evidence. “This trial matters not to persecute an individual, not to exact revenge on an opponent, and not to win in politics,” she said. “Judge this case by the evidence.”The prosecution argued that the four Articles of Impeachment collectively depict a pattern of abuse of power, betrayal of public trust, and lack of accountability.The defense offered an equally forceful counter-narrative. Lead counsel Sheila Sison portrayed the impeachment as an attempt to overturn the democratic mandate given to Duterte by more than 32 million voters in 2022. Invoking the country’s anti-dictatorship slogan “never forget,” she argued that constitutional safeguards, not political passions, must guide the proceedings.She accused the House of conducting a “mini trial” and a “fishing expedition” before the case reached the Senate and insisted that Duterte remains entitled to the full protection of due process.Neither narrative should be accepted uncritically. That is precisely why impeachment trials exist—to replace political accusation with judicial examination.The absent respondentYet the day’s biggest political message came not from either legal team but from Duterte herself. The vice president chose not to attend the opening session, instead appearing through her lawyers. She described personal testimony as “a matter of legal strategy and constitutional rights,” while her counsel correctly noted that Senate impeachment rules allow respondents to appear through counsel.Legally, the decision was entirely permissible. Politically, however, it came at a cost.Impeachment is more than a legal proceeding; it is also a public exercise in accountability. Citizens reasonably expect senior elected officials facing grave allegations to confront the process directly. Duterte’s absence inevitably fueled criticism from prosecutors who viewed it as disrespectful to the impeachment court.Still, political optics must not overshadow constitutional principles. The vice president’s decision to stay away cannot be treated as evidence of guilt, just as her presence alone would not establish innocence. The Constitution places the burden squarely on the prosecution. If it proves its allegations through credible documents and witness testimony, conviction would be warranted. If it fails, acquittal must follow regardless of political pressure or public opinion.The larger testThat principle becomes even more important because the trial unfolds against the collapse of the Marcos-Duterte alliance that swept the 2022 elections. The former running mates now stand on opposite sides of the country’s most significant political divide, fueling competing claims that the impeachment is either a necessary act of accountability or an attempt to sideline the administration’s strongest electoral rival.The Senate’s credibility will therefore depend less on the final verdict than on whether Filipinos believe every witness was fairly examined, every piece of evidence properly weighed and every ruling anchored in the Constitution rather than partisan calculation.Only one Philippine official, former Chief Justice Renato Corona, has ever been convicted through impeachment. Former President Joseph Estrada’s trial collapsed amid political upheaval, while other impeachment cases ended in resignation before judgment. Duterte’s trial thus becomes another defining test of the country’s constitutional order.Its significance extends well beyond Manila. Across Asia, democracies continue to wrestle with the tension between political competition and institutional accountability. Their durability is measured not during periods of consensus but when powerful rivals submit their disputes to constitutional processes rather than political force.Ultimately, this impeachment is testing two questions at once: whether Sara Duterte remains fit to hold public office, and whether Philippine democratic institutions are strong enough to decide that question through evidence, due process and the rule of law.The answer will shape not only the 2028 presidential race but also public confidence in Philippine democracy for years to come.