Brian Winter has a fascinating story in Americas Quarterly about the link (which I did not know about) between Joe Biden and Dilma Rousseff. It's a very personal story, the conclusion of which is that Dilma loves him.
Rousseff marveled to her aides: “That man could sell an icebox in Canada.”
Check it out. It serves as yet another layer of complexity that cuts through the typical and simplistic "The U.S. is ignoring Brazil" or "Brazil is pushing back against the United States" stories we tend to get. There's a lot more to it.