Sorry, I'm a latino, Mexicano, living in México, so I don't really have the slightest idea of how did this happen. Can someone give it a try?
EDIT: While I appreciate all of your replies, I'm even more confused as I see people mentioning "hispanic americans" as a synonym for "latino". This was an interesting read about the confusion. However, the reasons seem to be addressed against Hispanic Americans, but the meme os against Latinos. It feels a bit artificial or even prejudicial. Sorry for this edit, I'm not really sure about what I'm trying to say.