Sara Duterte resigned as education secretary in June 2025, citing "irreconcilable differences" with the administration. Since then, she has emerged as the administration's most vocal critic, particularly on the South China Sea disputes where Manila has taken an increasingly assertive stance against Beijing's territorial claims.

For ASEAN watchers, the impeachment push represents more than domestic political drama. The Philippines' pivot toward the U.S. under Marcos Jr. has made it an outlier in a region that generally prefers hedging between Washington and Beijing. An impeachment trial would likely become a referendum on that foreign policy shift.

The Senate, where a two-thirds majority is required for conviction, presents a higher bar. But the House vote alone would be politically damaging for Duterte, who is widely seen as positioning for another presidential run in 2028.

The anniversary timing of the vote-gathering effort is not coincidental. One year ago today, Rodrigo Duterte became the first former head of state from Southeast Asia to be arrested for ICC crimes, specifically for his administration's brutal drug war that killed thousands. The younger Duterte's impeachment would effectively sideline both father and daughter from the political mainstream.

Sandro Marcos, 31, has emerged as a key power broker in his father's administration despite his youth. His success in corralling votes demonstrates the enduring strength of the Marcos political machine in the House, where patronage and party discipline remain the dominant currency.

Neither Sandro Marcos nor Sara Duterte's camp responded to requests for comment. The House is expected to formally file articles of impeachment within the next two weeks.

Ten countries, 700 million people, one region – and in the Philippines, the battle between two dynasties is reshaping how Southeast Asia's most vocal democracy positions itself between superpowers.