An authoritarian populist with a taste for off-colour humour and a promise to shatter his country's political establishment has risen to become one of the leading contenders for his nation's presidency. Donald Trump? No, actually Rodrigo Duterte, mayor of Davao City, and new frontrunner in the Philippine presidential election, scheduled for 9 May.

Duterte made headlines over the weekend for refusing to apologise for remarks he made in the heat of a hostage crisis in 1989. On being told that a gang of prison inmates had raped one of the hostages they were holding, an Australian missionary named Jacqueline Hamill who later died in the attack, Duterte reportedly said that the victim was so beautiful that "the mayor should have been first".

Though he has now apologised for the comment, Duterte is well-known for not talking like a typical politician. He called Pope Francis the "son of a whore" after a papal visit to Manila caused huge traffic jams − this in a country where 86% of the population are Roman Catholic. He once reportedly forced a hapless tourist to comply with the city's smoking ban by making him eat his own cigarette butt.

He is also notorious for other reasons, especially his alleged facility with extrajudicial killing of criminals. A vigilante group, known as Davao Death Squad, is responsible for hundreds of murders of drug dealers and petty criminals over the years of his tenure. According to Human Rights Watch (HWR), he has admitted having links to the group, although he told Al Jazeera: "That's impossible, I do not need to set up death squads".

For context, Duterte came to power in 1988 in a city known to international media as the murder capital of the Philippines, due in large part to a communist insurgency. Over the years Duterte both tamed the insurgency and pursued a ruthless war on crime. Precise statistics are hard to come by, but it is clear that murder rates have significantly fallen and the city's citizens perceive it as a far better place to live. Duterte has been elected to the mayoralty no fewer than seven times.

Philippine politics are typically uproarious, but Duterte is exceptional. He provides an interesting test of the theory that, in politics and public life, rarely backing down or apologising can be a remarkably successful strategy, the better to appear strong and masculine. Trump might brag about the number of his great business deals, but Duterte seems to brag about the number of criminals he has killed.

"We're the ninth safest city. How do you think I did it? How did I reach that title among the world's safest cities? Kill them all," Duterte reportedly said last year. Last year he also allegedly threatened that if he became president, he would feed fish in Manila Bay with 100,000 criminals.

Trump might brag about the beauty of his model wife, but Duterte brags about the size of his harem, which includes at least one common-law wife and two girlfriends.

The contrast with his main rival, American-educated Grace Poe, could not be starker. Poe, a neophyte senator, trades on her image as the quasi-virginal Madonna of Philippine politics, unsoiled by the taint of corruption (an image she intelligently accentuates by usually wearing white in public). Her policies are the equivalent of a supermarket's own-brand range; bland fare but appetising enough. She is reported to be reasonably charismatic, though not given to barn-burning rhetoric.

Against her relative lack of experience, however, Duterte can cite his years of leadership at a local level, and a range of surprisingly liberal policies. A qualitative study from 2012 (Laya & Marquez) interviewed a number of Davao voters, and participants cited as reasons for Duterte's popularity his social programmes, such as additional financial support for teachers, academic scholarships for underprivileged children and free healthcare provision for the city's poorest. He is a well-known supporter of LGBT rights and has made positive noises about same-sex marriage.

Again, the parallels to Trump write themselves; moderate, liberal views on broader issues allow the candidate to present an extreme view on one single issue close to the hearts of voters (immigration for Trump, crime for Duterte), without necessarily appearing to be an extremist. Both present themselves as a Herculean candidate, fit to clean the Augean stables. Where Philippine politics are bedevilled with corruption scandals, American politics are drifting towards oligarchy.

Their success is, naturally, nauseating to most right-thinking, well-educated, affluent people. At the Good Judgment Open forecasting platform Duterte is still not quite ranked as the favourite, for all that he and Poe are the only candidates at this point with any chance of winning, and he appears to have the edge over her in recent polling. Just as the belief that world is innately just has prevented the media from evaluating the Trump phenomenon correctly, so, I suspect, has it prevented us from predicting Duterte's rise.

Given some combination of economic and/or social dysfunction, a discredited existing political order, and a sufficiently charismatic candidate, the rise of unpredictable demagogues would appear to be a recurrent feature of democracy. In itself, this is not necessarily disastrous; it can be viewed as a necessary, healthy feedback mechanism for the people to communicate to elites that, in the view of the people, the elites have taken a wrong turn.

The solution to this issue is clearly not to fiddle with electoral procedures for the benefit for establishment candidates; or, at any rate, one must not to do so too blatantly. That way lies eventual civil unrest. Far preferable to design and erect political institutions that place strict, unbreakable limits on executive power, and that can survive a term or two of rule by an authoritarian with little regard for established customs. The next decade may well provide many developed and developing nations with a good test of the robustness of their institutions.

It must always be remembered that supreme power lies, in any nation, in the hands of those who hold guns. For that reason the training and ultimate loyalties of a nation's officer corps are always of decisive importance. It surprises me that such a vital issue receives so little attention in our political discourse.

Rodrigo Duterte was contacted for comment by IBTimes UK but had not responded by the time of publication.