The former Davao City mayor, nicknamed "The Punisher", rose to power in a presidential campaign centered on fighting crime, encouraging extrajudicial killings as a key solution. He's even authorized the gun-carrying public to kill drug addicts and criminals themselves.
His actions are now sparking alarm that the country might spiral into lawlessness.
"Duterte is steamrolling the rule of law and its advocates both at home and abroad," said Phelim Kine, Asia deputy director at Human Rights Watch (HRW) in a statement this week, noting that the President was breeding a violent society.
The Philippines has long battled a history of drug-related violence, making Duterte's commitment to eradicating crime especially appealing to the bulk of the population, which won him 40 percent of the vote in the May election. A July opinion poll revealed he enjoyed a 91 percent approval rating, indicating solid support not only for his war on drugs but the sexist remarks, diplomatic blunders and threats to the business community that have marked his reign thus far.
A few domestic voices have lashed out against the President, including the Catholic Church and Senator Leila de Lima. In response, Duterte has flagged the Church's hypocrisy, particularly its wealth and priests' abuse of children, and accused de Lima of having an extramarital affair and accepting illegal campaign contributions.
Domestic institutions are effectively powerless to stand up to the President, strategists say.
"Duterte was elected with only a handful of congressional allies. But because Philippine political parties are weak, he now has the support of most legislators who simply switched sides after his victory in search of presidential patronage. This has left only a few critics in office to speak out against the crackdown," Mark Thompson, director of the Southeast Asia Research Centre at the City University of Hong Kong, and Ronald Holmes, research scholar at the Australian National University, wrote in an editorial for Caixin.
Even the Supreme Court holds little sway over Duterte. The legislative body has been politicized following the Chief Justice's removal by former President Benigno Aquino in 2012, Thompson and Holmes noted.