Gustavo Petro, a former senator, was elected president of Colombia in 2022 after a career on the left of Colombian politics. In his youth he belonged to the M-19 guerrilla movement, which demobilised and entered legal politics in 1990. Opponents have used the guerrillero label against him ever since, and the short Petro guerrillero phrase circulates online as a compact version of that attack, shared in political memes, short videos and messaging chats far beyond formal campaign material.