Sorry, my friend. Hispanus and hispanicus were in use before there were Spaniards, let alone before they conquered anyone. Both terms designated those who came from Hispania, which as I said, is primarily modern day Spain. Hispania referred to the entire Iberian Peninsula, but Spain was conquered by Rome, and it’s denizens thus carried the name prior.
Hispanic (Spanish: hispano, hispánico) is a term that originally denoted a relationship to Hispania. The term Hispanic was first adopted by the United States government in the early 1970s, during the administration of Richard Nixon,[1] It has been used in the U.S. Census since 1980.[2] The term hispanic is seen as a false cognate with a limited meaning from the original historical term "hispanicus".[3] Since it was adopted by the USA government for the first time, the concept of "hispanic" has been changing along the time. Who is considered hispanic can differ from state to state or differ according to the requirements of the different organizations.[4]
Please note the dates and the entry of PC definitions in our society.
Opps, forgot this: http://en.wikipedia.org/wiki/Hispanic