Colombia’s left-wing and progressive coalition, Pacto Historico, has become the country’s most popular political movement following the congressional elections on Sunday, March 13. This historical victory threatens two hundred years of ruling-class hegemony, with most of the coalition’s representatives coming from campesino and working-class backgrounds. Depending on what happens in May’s presidential election, this win could have global reverberations. Crucially, the West stands to lose the unconditional loyalty of its most stable ally in the region.

Gustavo Petro, the coalition’s presidential candidate, comes from a family of rural workers who, like many in the country, were forced to migrate toward the capital to escape poverty and violence. As expected, Petro won the coalition’s primaries with more than four million votes. Francia Marquez, a rural black activist within the alliance, also made history with close to a million votes — more than all the mainstream candidates received in their respective primaries, and despite having never held a political post.

Although the progressive coalition is the most dominant political force in the country, the center and right-wing parties are now forming their alliance to impede their progress toward the presidency in May. What happens next depends on Pacto Historico’s ability to mobilize first-time and swing voters and persuade the more popular center parties and leaders to join the coalition, a feat Petro failed at in the 2018 elections.