Nine months away from mid-term elections that could determine the success or failure of his presidency, his daughter, Sara Duterte, is fast emerging as a power-broker who is aiming to shore up support for his ambitious policy agenda, and, say some experts and insiders, his eventual succession.
By his own admission, the 73-year-old president is flagging. On Tuesday, he lamented his uphill struggle to tackle illicit drugs and cut state corruption, predicting that he'll "hardly make a dent" in his remaining four years in office.
During a ceremony and again at a dinner afterwards, he said he was tired, exasperated and thinking about quitting, and ended his sombre, one hour, 20 minute speech with: "I'm telling you, I'm ready to step down and retire."
That contrasts sharply from his 40-year-old daughter, who has started manoeuvring to build alliances and expand her small party in the southern Davao region into a new political juggernaut, as fissures appear in her father's ruling PDP-Laban party.
She was instrumental in bringing together political factions to stage a dramatic July 23 ousting of divisive Duterte ally Pantaleon Alvarez as lower house speaker, replacing him with veteran Gloria Macapagal Arroyo, 71, a former president with clout and connections to ensure support for Duterte and his agenda.
The move was helped by a relationship developing between Sara Duterte and Imee Marcos, 62, a provincial governor and key figure in the still influential family of late dictator Ferdinand Marcos, who ruled the Philippines for two decades before being ousted in a 1986 uprising.
The two women posed together for pictures last week, each with one hand doing Duterte's trademark clenched fist, and making a "V" sign synonymous with the rule of Marcos with the other.
Rodrigo Duterte's rise has been a boon for the Marcos family. Imee Marcos frequently attends his official events and in 2016, Duterte granted her longstanding wish for her father to be buried with military honours at a Manila heroes' cemetery.
Duterte also said last week that if he steps down, her brother, Ferdinand Marcos Jr, a former senator better known as "Bongbong", would have been a capable replacement for him.
Marcos Jr came a close second to Leni Robredo, a rival of Duterte, in the 2016 vice presidential election, but he has challenged the result in the Supreme Court.
"NEW CENTRE OF GRAVITY"
Richard Heydarian, an author, columnist and academic who specialises in politics, said the Marcos family wanted to stay relevant nationally and in a political culture where loyalties easily shift, Sara Duterte was now widely seen as a figure worth rallying behind.
"People around (Rodrigo) Duterte are looking for a new centre of gravity. They see signs of an exhausted president and see there could be some kind of succession that can protect their interests," he said.
"He has a very shallow network of politicians, he's not at his peak. He just has to hold on as long as he can."
Duterte acknowledges that, and on Tuesday said he can't resign because a constitutional succession would mean handing power to opposition leader and vice president Robredo, who was elected separately. He said Robredo isn't up to the job - which she refutes - and he'd prefer a junta takes over.
Duterte's relationship with daughter Sara has however often appeared rocky and she has portrayed herself as his reluctant successor as mayor of Davao City.
Like her father, she is feared and respected, and known for being blunt, unpredictable and for openly trading barbs with the president.
Despite that, few doubt her loyalty to him. Although she denies being interested, she and other Duterte allies, including his spokesman, his special assistant and his former police chief, are tipped to run for the 24-seat Senate in 2019, as is Imee Marcos.
That could be a game-changer for the president, who has built a strong majority in the House of Representatives but needs control of the upper house to deliver on his promises.
Among a raft of plans, he wants to redraft the constitution and deliver his centrepiece economic policy, a $180 billion infrastructure spree designed to modernise the country, spur spending, create jobs and lure investment.
"Now is the chance to further consolidate power by controlling both houses of congress and the local government units so all of us can we move forward in cadence," said a member of a nine-party alliance formed by Sara Duterte last week.
He requested anonymity, saying only Sara Duterte could speak about the alliance.
"The goal is, fill the Senate with people who can help ... We don't want people who will only obstruct his plans."
Opposition lawmaker Antonio Tinio said Rodrigo Duterte was essentially a local politician thrust into the presidency and needed national level allies.
"Hence, his alliance with the Marcoses and Gloria Arroyo," he said.
Tinio is sceptical about Duterte's talk of retirement and is among many opponents who suspect he'll try to continue beyond his permitted single six-year term - an idea Duterte this week said was idiotic.
Plan B, Tinio said, was his daughter succeeding him.
"If efforts to extend the term of President Duterte through charter change fail, it's very likely that the Dutertes' Davao formula for dynastic succession will prevail," he said.
