FROM REDDIT : "Are Basque surnames associated with upper class people in your country?"

[Etelfrido]

Yep, one of ours president was of Basque ancestry

But I don't think Basque surnames are common enough for we Brazilians to have any stereotype on them, even in the case of the president you mentioned he's known by his non-Basque surname Médici.

[axel.aleman]

No necesariamente

Pero se extraña a RMuller, una de las leyendas del foro