As goes Brazil, so goes democracy? It is no good outsiders pouring contempt on Jair Bolsonaro, victor in Sunday’s Brazilian presidential election. He is the choice of his people. For non-Brazilians, it is what he represents, not what he says, that matters.

Brazil has been one of the world’s most exciting emergent nations, yet its evolution over 30 years from dictatorship to hesitant democracy seems to have stalled. Bolsonaro has exploited the oldest politics, that of self-interest, and also the newest, that of anger, polarisation and fear. Voters have stomached his distaste for gay people, feminism, rainforests and the rule of law, to rid themselves of a corrupt leftwing regime unable to contain street violence. A famously tolerant nation has opted for military and economic discipline.

In any country, the apparent breakdown of social order will drive voters to extremism. This message has proved popular around the world, from Rodrigo Duterte of the Philippines, Andrés Manuel López Obrador of Mexico, Viktor Orbán of Hungary, Recep Tayyip Erdoğan of Turkey, even America’s Donald Trump. Liberal values, however defined, will not survive when their defenders cannot transmit their virtues to voters.

The lesson for champions of open democracy is glaring. Its values cannot be taken for granted. When debate is no longer through regulated media, courts and institutions, politics will default to the mob. Social media – once hailed as an agent of global concord – has become the purveyor of falsity, anger and hatred. Its algorithms polarise opinion. Its pseudo-information drives argument to the extremes. Even an apparently stable democracy such as Germany this week finds its centrist consensus torn apart, as the electorate divides between far right and radical left.

Profile Who is Jair Bolsonaro? Show Biography Born in Glicério in São Paulo in 1955 to parents of Italian descent, he served in the army from 1971 until 1988, when he was elected as a city councillor in Rio de Janeiro for the Christian Democratic party. In 1990, he became a federal congressman for the same party. He has since been affiliated with a number of political parties. On 22 July, he was officially nominated as the presidential candidate of the Social Liberal party. Policies Bolsonaro espouses populist and nationalist views that often stray into far-right territory. A vocal opponent of same-sex marriage, abortion, immigration and other progressive causes, he has defended the death penalty and the 1964-85 military dictatorship. On foreign policy, he has said he wants to improve relations with the US. Economically he says he is pro free market and privatisation. Political style Deliberately provocative and polarising. He has praised Gen Pinochet, expressed support for torturers and called for political opponents to be shot, earning him the label of "the most misogynistic, hateful elected official in the democratic world”. In his bid to capitalise on Latin America’s lurch to the right, he paints himself as a tropical Donald Trump: a pro-gun, anti-establishment crusader set on "draining the swamp" and cracking down on violent crime. Controversies On top of repeated calls for a return to dictatorship, he has made equally inflammatory attacks on women, black people, gay people, foreigners and indigenous communities. Earlier this year, he was charged by the attorney general with inciting hate speech. Support and first round victory Bolsonaro has a devout following among some conservative voters, who admire his promises to get tough on rampant violent crime, and won 46% of the vote in the election's first round. Photograph: Evaristo Sa/AFP

Every continent is now seeing the emergence of (mostly) rightwing disrupters. They appeal to those who feel excluded by “identity politics”, by what they perceive as liberal pandering to minorities. They feed on religious intolerance and on neighbourhood insecurity. They spit anger at any form of establishment. Yapping in their van are the jackals of social media, spreading fear.

In the light of the rise of the new right, it is not enough for liberals to stay silent. Lies and hatred cannot be purveyed across the globe for profit. Hysteria and anger cannot become standard political discourse. The boring modalities of democracy – regulating elections, curbing censorship, taming extremism, fighting corruption – all matter crucially.

Democratic leadership is becoming inured to moderation. Britain is no exception. What should be a sensible debate over trade policy has become polarised and polluted with anger. Coalition and compromise appear impossible. The outcome could yet be disastrous. That is the message of Brazil.

• Simon Jenkins is a Guardian columnist