Well, I don't think the United States will still back this up as much as they used to back in the 1800's and such. Plenty of corruption happen in South America within their own [countries] borders, yet the US doesn't get involved at all. Plus our old enemies Britain and Germany, at the time, could've invaded South and Central America at any time. That's why we set up the Monroe Doctrine in the first place.
We don't have any current events that proves that the Monroe Doctrine is still in effect because our old enemies are Allies or chill with the US. We do however get involved anything threatening to the US such as the spread of communism and terrorististic affiliations against the US.