Racial Impersonations

What gives one the idea that impersonating and in turn mocking another race or ethnicity, based upon stereotypes created by the dominant ideology, is acceptable in any situation or scenario? In my mind imitating a people by means of cultural cliches is an act that should never be committed in private or public, much less on a screen for the viewing pleasure of an audience lusting for entertainment. First of all the existence of stereotypes in our society is unfortunate enough, but to raunchily entertain a group of  people at the expense of another is unnecessary and uncalled for.  The fact that these overt acts of racism have constructed the foundation of America's film industry, or shall i say pervaded the entertainment industry as a whole, and continue to be exhibited today in a variety of ways indicates something about American culture's dominant ideology. Not only does this fact solidify the idea of "white privilege" in America it exhibits an imbalance between "ethnicity" and "whiteness", in that throughout history whites have in a multitude of ways attained their status, privilege and dominance at the expense of non-whites, or "Others." A historical example of this racially based impersonation can be seen in the first film with synchronized sound called The Jazz Singer. In this film a Caucasian Jew sings in a Broadway performance wearing "Blackface", which is the use of face-paint and other props to imitate an African American. This racial mimic is completely, one-hundred percent irrelevant to the content of the film and is a prime example of acting out a stereotype for the sole purpose of comedic entertainment. A more contemporary example of this racial imitation can be seen in the Wayan's brother's film White Chicks, which is a comedy revolving around the impersonation of two white females by two African American men. It seems racially based entertainment and comedy are prevalent throughout society but i do not consider this issue to be one of any comical connotations and is not something to take lightly.