Castillo leads in Peru, but will he be able to govern?

The 2021 presidential election in Peru was an nasty, hyperpolarized affair filled with misinformation and violence. All this, amid a deadly pandemic which Peru has struggled to manage. So it was fitting that the election would have the most dramatic of denouements, with far-left candidate Pedro Castillo only pulling ahead of his far-right opponent, Keiko Fujimori, at the very last minute.

Yet, Mr. Castillo’s toughest challenges are still to come. 

Given his excruciatingly tight winning margin, he will face immediate questions about his legitimacy — even more so because the elites in capital city Lima overwhelmingly turned out in favor of his opponent. Ms. Fujimori is demanding a recount amid unproven allegations of voter fraud. (Indeed, Mr. Castillo’s far-right opponent has previous in this regard: she lost the 2016 election to Pedro Pablo Kuczynski by a margin of just 41,000 votes.)

Add to that the recurring fears of Latin American conservatives when faced with a left-wing government in favor of expanding the state, and the fact that a congressional majority is little more than a pipe dream. 

Governing will be tough, especially considering that Peruvian lawmakers have a trigger-happy track record when it comes to unseating presidents no longer seen as suitable.

During the runoff campaign, both Mr. Castillo and Ms. Fujimori gestured toward the center. In the case of the far-left leader, this meant removing references to Marxism from the first paragraph of his manifesto. Granted, Mr. Castillo’s plan is not moderate, including calls for a new constitution and plans to renegotiate mining and gas contracts.

Close to achieving victory by way of...