ON JULY 1st Mexicans are set to elect Andrés Manuel López Obrador as their next president. Since they twice rejected him, in 2006 and 2012, by coalescing behind the opponent with the best chance of winning, that requires some explanation. Mr López Obrador is of the left, but he is a would-be saviour rather than a social democrat. Instead of a better future, he promises to return Mexico to a better, safer past of strong, paternalist government. He invites voters to trust in him, rather than in democratic institutions. As the last two contests showed, in normal circumstances he would not win.

But Mexicans are not looking for politics as usual. Under the outgoing president, Enrique Peña Nieto, they suffer rampant crime and corruption, and mediocre economic growth. Each day 85 people are murdered. Voters “want blood”, in the form of systematic punishment of corrupt politicians, according to Jorge Castañeda, who is advising Ricardo Anaya, Mr López Obrador’s closest rival. Many think that centrist politicians have failed them and that things cannot get any worse.

Brazilians are in a similar mood ahead of their election in October. Most are not yet focused on it, but one of the front-runners in the opinion polls is Jair Bolsonaro, a crudely authoritarian, misogynistic and homophobic former army officer. Brazil, unlike Mexico, has a run-off vote; Mr Bolsonaro may well figure in it but is unlikely to win it. Nevertheless, that he has a chance is a sign of desperate times. Brazil is only slowly emerging from a two-year slump, public services are stretched and public security has broken down in many parts of the country. A recent poll found that 62% of respondents aged 16-24 would leave if they could.

It is not the first time Latin Americans have turned, in an emergency, to would-be saviours. In 1990 voters in Peru found one in Alberto Fujimori, an obscure former university rector. A political outsider, he was elected when his country faced a terrorist insurgency, hyperinflation and economic meltdown. When he sent tanks to shut down the congress two years later, polite society was appalled but ordinary Peruvians cheered. Mr Fujimori won a second term in 1995.

Or take Venezuela. The collapse of the oil price in the 1980s and 1990s weakened a stable social democracy, hollowing out its welfare state, causing bank failures and exposing corruption. In anger, Venezuelans turned to an army lieutenant-colonel, Hugo Chávez, who had led a failed coup that crystallised popular disillusion with the established order. Chávez was elected in 1998. As the oil price surged again, he became a popular hero. But long before his death in 2013 he had propelled his country towards its current feral state of corruption, brutality and penury.

Colombians in 2002 were suffering the tightening grip of the FARC guerrillas over much of the national territory as well as a recession and a banking crisis. They normally chose moderate presidents, but they elected Álvaro Uribe, an intense conservative who promised to be “the first soldier of Colombia” and to double the size of the security forces.

Mr Fujimori and Mr Uribe saved their countries, but in both cases there was a dark side. Mr Fujimori governed as a dictator and resorted to systematic bribery. Mr Uribe appointed officials with links to right-wing death squads.

When voters choose candidates they normally wouldn’t, the negative consequences are long-lasting. In Venezuela, Colombia and Peru these include political polarisation. Peru is trapped in a battle between Mr Fujimori’s supporters and anti-fujimorismo. Mr Uribe’s candidate, Iván Duque, won Colombia’s presidential election on June 17th, but he inherits a country that is “divided, polarised and facing off against itself in a seemingly irreconcilable fashion”, as Juan Gabriel Vásquez, a Colombian writer, put it in El País, a Spanish newspaper.

The saviours never give up. Mr Fujimori’s daughter runs what is still Peru’s biggest political party. Not for Mr Uribe, who was re-elected to the senate, the example set by Mariano Rajoy, Spain’s former prime minister. After parliament ousted Mr Rajoy this month he returned to his job of 37 years ago as a property registrar in a quiet coastal town.

This lasting polarisation is what may face Mexico and Brazil. It is the high price that countries pay when the political establishment fails in its most basic functions of protecting the lives of citizens or preventing the pilfering of public money. When that happens, it is hardly surprising that voters look elsewhere. But the problem with saviours is that, sooner or later, countries have to try to save themselves from them.