I’d say South America has always been pretty much a mixed bag in the preferred brand of tyranny, often alternating between left and right in the same country. Although historically my impression is that the more genuinely committed ideologues incline to the left while the right-wing dictators seem more like opportunistic thugs in epaulets happy to call themselves anti-communist in exchange for handouts.
Was Somoza, for instance, really committed to much else than himself?