Fascism, Falange (Spanish Fascism) and Nazism has existed in Latin America since the early 1930s, those were ultra-nationalist, xenophobic and fanatic groups that wanted to take control of the country from the oligarchal liberals and conservatives (who had by that point ruined the country). Some groups failed spetacualy during the coup attempts, though they did manage to influence some military groups during the 1930s - 1940s. Most of them got banned by the late 1930s, and were basically dissolved by 1946.

After that they divided into three groups: Those who got into mainstream politics and became a part of the Military Juntas of the 1960s - 1980s (as seen in Argentina, El Salvador, Brazil, Uruguay and Chile). Those who became irrelevant and kept doing their weird brown shirt stuff and no one cared about them. And those who became far-left fighters mostly because they hated the US or had a genuine change of ideological views (as seen with Priest Helder Camera in Brazil and weird people like José Joe Baxter who was a nazi in his youth and became a trot, peronist and maoist and joined the vietcong to fight the Americans, he was killed by the CIA when he was helping the Sandinistas in Nicaragua).

Neo-Nazism as seen here, existed since the late 1980s, but it got really popular around the early 2010s thanks to the Conservative Wave and the popularity of Western Social Media. Neo-Nazis are still seen as bad people, and most people usually avoid association with them.