I have always believed that acting involves an individual pretending to be someone he (or she) is not and using his (or her) skills to convince an audience of his (or her) authenticity. A recent film version of David Copperfield involved an actor of Indian ethnicity, Dev Patel playing the lead role. His performance wss excellent and his ethnicity was unimportant. Some years ago, the National Theatre production of Carousel fielded a black actor in the role of Enoch Snow.
However, in recent times, it appears that approaching this matter from the opposite direction is unacceptable. Therefore no caucasian actor is permitted to appear on the stage as - say - Othello.
A few years ago, at the Proms, John Wilson performed West Side Story and his intended Maria was Sierra Boggess, probably the best female musical theatre performer around. She turned down the opportunity to appear on the grounds that she was not "hispanic". My understanding of "hispanic" is ... well ... Spanish, a cultural rather than ethnic concept. Hy observation of Spanish women when I have visited Spain, is that they are indistinguishable from women from elsewhere in southern Europe, mainly - but not always - a little darker than women from elsewhere in Europe but still essentially caucasian. My suspician is that Americans have redefined "hispanic" to mean native Central Americans.
I can imagin the fuss there would be if some film director did not employ a Scottish actor to play Bonny Prince Charlie - whose first language was probably Italian!