Latin America is already 35-40% European descent. Brazil, Argentina, Uruguay, Cuba, Costa Rica, Chile, etc all have very high percentages. Venezuela and Colombia have fair percentages 30-42%. Mexico has upwards of 10-15% which is a very large populace for its 100+ million inhabitants. Dominican Republic is at the low end with 16% and other nations such as Nicaragua, Honduras, Peru and Bolivia are below 10%.
I mean, Brazil is the third largest nation on earth in terms of 'white' or European descent, only behind the US and Russia. So, what more do you want?
European descent doesn't cut it here. Probably 'one drop' policy applies, seeing as the OP specifies
In our timeline, the Spanish and Portuguese conquistadors engaged in miscegenation with both the indigenous population and Africa slaves which resulted in the racially-mixed population in Latin America today.
1). The conquistadors bring their own women to the Americas.
2). The Catholic Church strictly prohibit miscegenation between whites and non-whites.
3). More massacres and smallpox epidemics happen.
4). Spanish and Portuguese authorities allow Catholics from Europe to immigrate to their colonies. Aside from more Spanish, Portuguese, and Italian families immigrating, many Dutch, German, and English Catholics immigrate to the New World as a result of the anti-Catholic sentiment arising due to the Protestant reformation.
So purely European.
Not sure what this is asking for, aside from imagining the virtual depopulation of the majority of South America. What, like the future developments of such an ATL? The plausibility of it?
The latter would be pretty unlikely, I think. The Iberians wanted to Christianize the new lands (as well as exploit it as much as possible) and killing off the whole native population goes against both goals (if you kill them, you can't convert them or use them as forced manual labor). Bringing in African slaves makes the situation even less likely to happen, as you can see in the American South's pre-Civil War demographics. No integration and pure slaughter means no help for the explorers, plus all the failed rebellions from the Inca would have way more support, so Spanish control starts to become untenable. No native allies from the start means the Spanish conquests get pushed back by a loooong time, if they do happen.
Industrial level genocide is a bit too early, I would say. I guess the smallpox could be worse but not actively, I'm not aware of the Spanish trying germ warfare at the time. It was mostly incidental.
As for future developments, all of South America is much less populated for centuries. It gets less focus, I should expect, because there's no way to extract as many resources as in OTL (like the silver from Potosi) without the forced labour from non-European folks. Spain isn't quite as flush with money, that sort.
Overall, you'd have to change quite a few peoples' mindsets and goals. But yeah, not practical, not ethical, and changes quite a bit.
