Populism has taken many forms amid the pandemic: in Peru, it arrived in a small Andean town on the back of a horse.

Pedro Castillo, the far-left activist who won the first round of Sunday’s presidential election, almost did not make it to vote at a school in Tacabamba: alarmed by crowds, his steed reared and bucked repeatedly, threatening to throw him off.

But Castillo clung on as helpers tugged repeatedly on the horse’s bridle and, after the ballots were counted, the scale of Peruvians’ disillusion with their politicians became clear.

Although voting was compulsory, nearly a third abstained; of those who did vote, over 17 per cent returned an invalid paper. “More people cast spoiled or blank ballots than voted for Castillo, who won first place,” said Cynthia Arnson, director of the Wilson Center’s Latin America programme. “That’s a deeply troubling sign.”

Best-known for leading a long teachers’ strike in 2017, Castillo barely figured in opinion polls until the final stages of the campaign. His advocacy of widespread nationalisation and calls to renegotiate state contracts and trade treaties have alarmed many Peruvians but they face an unenviable choice.

His likely opponent in a run-off election in June is Keiko Fujimori, daughter of former strongman president Alberto Fujimori, who is serving a long prison sentence for human rights abuses and corruption. Keiko is herself under investigation for allegedly taking millions of dollars in illegal campaign funding.

Marta Lagos, director of Latinobarómetro, a regional polling organisation based in Chile, said Peru was an “extreme case” of the populism sweeping Latin America.

“You have two candidates reaching the second round who are totally outside the traditional political establishment,” she said. “It is also a magisterial example of a country which has gone from having a party system to having no [viable] parties.”

As Latin America goes through a big election cycle, with seven major nations holding presidential or midterm elections by October this year, voters are venting their fury at a political class that is seen to have failed.

The region is the world’s worst hit by the combined health and economic impact of coronavirus, according to the World Bank. This has exacerbated grave “pre-existing conditions” — glaring inequalities of income and opportunity, uncompetitive economies and inadequate public services.

Underlining the unpredictability of regional politics, Ecuador also voted last Sunday and chose as president Guillermo Lasso, a self-made millionaire and former banker, in a result seen as a repudiation of the leftist populism espoused by the losing candidate. As in Peru, the winning candidate is far short of a congressional majority, heightening the challenges of governing.

After Peru and Ecuador, the next Latin American nation to vote is Chile, where electors will in mid-May choose delegates to a special assembly to draft a new constitution. A few months later, they will pick a new president.

One of the region’s best economic performers, Chile lost its halo when riots erupted in October 2019 over costly public services, inadequate pensions and eroding living standards.

The Pacific nation had stood out for its consensus politics over the past three decades, with power alternating between the centre-left and centre-right. Now one of its most popular politicians is a former television presenter, Pamela Jiles, best known for promoting early withdrawals of pension savings.

Even though economists point out that repeatedly pulling out pension funds early will only make retirement finances worse, some lawmakers from the governing centre-right coalition are backing such moves.

Nicholas Watson, Latin America managing director at the consultancy Teneo, said this illustrated one of the biggest dangers of the region’s current wave of populists: their ability to panic established politicians into adopting ill-considered measures that they would normally have resisted.

“You get this sort of populist creep,” he said. “You don’t need even to be in power. The fact you exist and have traction with the population sways politics towards more radical policy proposals.”