It’s too soon to say whether tomorrow the arch-libertarian Javier Milei will be able to convert his place from leading contender to become Argentina’s president-elect. There might have to be a runoff. It’s not too soon, though, to savor the prospect of a free marketeer and sound money advocate acceding to the Pink House. Particularly in the land that spawned Perónism and whose name — Argentina —  means money.

The anarcho-capitalist is campaigning with a chainsaw, vowing to upend Argentina’s establishment, which he describes as a “political caste” of “useless parasites.” It’s “no time for nice words and good manners,” he avers, noting that, as the Wall Street Journal reports, “the caste is trembling.” The anger, if strident, is understandable, with Perónism, a leftist hybrid of nationalism and statism, having ravaged the once-thriving Argentine economy.

Poverty stands at 40 percent in a country that once vied with America as a contender for economic superpower status. Inflation is running at a catastrophic 138 percent, devastating Argentines’ buying power and driving a black market in dollars. No wonder Mr. Milei wants to ditch the country’s debased peso, which he calls “a currency emitted by Argentine politicians” that isn’t even “worth excrement,” because the pesos can’t be used as fertilizer. 

The real path toward restoring sound money in Argentina would be to restore a peso convertible into gold or silver, as opposed to merely adopting a fiat dollar. Yet Mr. Milei’s proposed “dollarization” — making the greenback Argentina’s sole legal tender — is something of a step in the right direction. It would mark a sea change for a country that has been notorious for its lax monetary and fiscal policies after it abandoned its gold standard.

That was in 1929. Since then, Argentina’s currency has fallen in tandem with the country’s economic prospects. As the 20th century began, both America and Argentina “were young, dynamic nations with fertile farmlands and confident exporters,” journalist and historian Alan Beattie has observed, and “Argentina was among the 10 richest economies in the world.” Emigrants fleeing Europe were often torn, he noted: “Buenos Aires or New York?”

Argentina’s prospects dimmed during the Great Depression. Instead of following America’s path by embracing global trade, Argentina fell prey to the siren song of Perónism. This regime of corporate cronyism and big government, as economist Lawrence Reed explains, “expanded the power of labor unions, spent lavishly on welfare schemes and waged class warfare against the rich,” and drove Argentina’s economy into the ditch.

One of the most insidious aspects of Perónism is how it inverted the formula of “negative rights.” These are enshrined in America’s Constitution to protect against the predations of the government, as seen in, say, the First Amendment, which opens by saying “Congress shall make no law . . .” By contrast, Eva Perón justified the socialist takeover of the economy and a bloated welfare state by saying “Where there’s a need, there’s a right.”

Mr. Milei is, in the Financial Times’ telling, running on a platform that is as far from Perónism as it gets, calling for “unfettered free markets,” free trade, and “giving primacy to private property and individual freedom.” The fact that he has named his dogs after economists like Milton Friedman, Robert Lucas, and Murray Rothbard suggests he has an awareness that political liberty is not possible without economic liberty.

Whether or not Mr. Milei wins the presidency in Sunday’s first round of voting, as he suggests is a possibility, or at all, his candidacy is a bright spot on a continent that has lately drifted toward the shoals of neo-Marxism. Observers call it a “pink tide.” The Argentines have the opportunity at the ballot box to buck this leftward trend, choosing sound money and individual liberty and putting their country on the path to prosperity it left decades ago.