the hooligan Duterte won't win. He'll do well to come second. Hicks like him don't get to be president. Only 3 of the 15 presidents that there's been, have been born on islands other than Luzon, and none at all, for fifty years. He is a bit like the Philippines' Donald Trump, who won't become president either. Duterte is running as an outsider and a Visayan nationalist outsider to boot however don't forget there are plenty more Filipinos that aren't Visayans than those who are. And the trouble with populism is that it isn't always as popular as it can seem. Duterte does appeal to some Filipinos, mostly but not all Visayan ones, but make no mistake, a lot of Filipinos, even Visayan ones, can see straight through Duterte and won't vote for him.
because the rest of the field is relatively lacklustre, that is why Duterte is rated to have any chance at all by so many. It is not an easy election to call even though the poll is only 100 days away, but I reckon Poe - now that her disqualification has been rescinded - will emerge the winner, making the Philippines the first country ever to have had three women presidents.