Following neoliberal reforms in the 1990s that enhanced inequality levels in South America, the region saw a wave of left-wing and center-left leaders winning elections in their respective nations. Benefiting from a once-in-a-lifetime commodities boom, these leaders beefed up social policies, oversaw a massive reduction of poverty and unemployment rates, and in some cases became larger-than-life figures with massive followings. Some of them, such as Venezuela’s late President Hugo Chávez and Bolivia’s former leader Evo Morales, used their power to change the rules and extend their time in office.
Others used a different approach: ushering allies into power to rule as presidents by proxy.
The latest of this new breed of leaders is Bolivia’s Luis Arce, who took office on November 8 after winning the presidential race in a landslide. While Mr. Arce is considered a skilled statesman, few would argue that his success is inextricably linked to his political godfather, Evo Morales — who was ousted in a 2019 military-backed coup and had been in exile for almost a year.
Mr. Arce has been in office for less than a month, but is already...