Hispanic is, as several have mentioned, a term that THE MAN created to LABEL us, the brown man. It is not a self-created label, thus it is bad.
Mexican-American is what I, and most, latino's call oursevles if we are decended from Mexico. Hispanic is broader, allows for all of those of Spanish-speaking heritage.
Plus, if you have to ask you probaby should not get to call yourself either.
odale vato