I would think that cartel violence is targeted enough not to qualify as a rampage shooting. Often they are perpetrated by larger groups of 10-15 armed men, and the victims are targeted because of their affiliation with another rival group. Yes, it's a mass killing, but it's a mass killing with a discrete purpose.
I would also think that a bit of the Republican hypothesis about guns holds up here: people don't perpetrate mass shootings where guns are ubiquitous because the risk of someone shooting back is much higher. Law enforcement in these places is often corrupt if they exist at all, so individuals take policing into their own hands by carrying weapons everywhere. But personally, I don't want to live in a country where I have to carry a gun to feel safe.
I would also think that a bit of the Republican hypothesis about guns holds up here: people don't perpetrate mass shootings where guns are ubiquitous because the risk of someone shooting back is much higher. Law enforcement in these places is often corrupt if they exist at all, so individuals take policing into their own hands by carrying weapons everywhere. But personally, I don't want to live in a country where I have to carry a gun to feel safe.