Cruz is not actually a Hispanic, he is a Cuban, and Cubans are NOT seen as legitimate members of the Hispanic community. They are seen rather as a bunch of mama's boys who were brought here and given special treatment for political reasons. Poor Mexicans in the Rio Grande Valley are NOT gonna vote for this lame peckerwood because his name ends in a Z.
The GOP oligarchy will tout him as a Hispanic as they did Mel Martinez, who they actually made some sort of puppet leader of the GOP. Of course, when he was of no more use to them them they stripped him of the title and forced him out of the Senate.