Duterte attacks Chelsea Clinton by bringing up her father's philandering

"When your father, the president of the United States, was screwing Lewinsky and the girls there in the White House, how did you feel? Did you slam your father?" he asked, in a reference to Monica Lewinsky, the White House intern with whom Bill Clinton had a sexual entanglement.

Clinton had attacked Duterte for saying that he would take responsibility for crimes committed by soldiers under his recently imposed martial law in the southern Philippines, even if they "raped three women."

"Not funny," Clinton commented on Twitter, before going on to respond to another user that "Duterte is a murderous thug with no regard for human rights. It's important to keep pointing that out & that rape is never a joke."

The Philippine President insisted on Wednesday he was just being "sarcastic" and then made a reference to the famous case of a trans Filipina woman, Jennifer Laude, who was killed by a U.S. Marine in 2014. Then, as if the internet had not heard it yet, he repeated the anti-Chelsea punchline - again in English - this time more crudely. He warned her: "Be careful because you live in a glass house."

Predictably, the remarks exploded onto social networks in the Philippines and the United States.

Duterte's attack tracks closely with a strategy employed by Donald Trump during his presidential campaign against Hillary Clinton. When Trump's alleged sexual abuses became a major issue, the reality TV star responded by attempting to put the attention on Bill Clinton's own sexual history.

Duterte has now attacked Obama, journalists, human rights campaigners, and Chelsea Clinton, but he has never attacked Trump, who recently praised Duterte's "unbelievable job" on his drug program. Thousands of people have died since Duterte's "war" on drugs began last year, and his government has been widely accused of human rights abuses.

But unlike Trump, Duterte has been a politician for decades, and analysts say he uses outrageous statements like this for a few strategic purposes. He brings attention to himself and shows his many devoted followers - he is especially popular here in Davao - that he won't take any lip. At the same time, he signals support to his allies, always being careful enough to avoid attacking friends.

"He knows how to dish out hot copy and like any political pro, keep the crowd entertained. This makes him go viral, and at the heart of it, he is doubling down whenever he feels someone is trying to go mano-a-mano," said Manuel L. Quezon III, a columnist and communications specialist who worked for the previous Benigno Aquino administration. "He considers himself friends with Trump and has said so because Trump has never raised the issue that infuriated him about Obama: human rights."

Over 20 years in Davao, Duterte built a loyal base of support. He's used to employing shock value, and the consequent outrage often rolls off the backs of people here.