Samuel L. Jackson went on the radio and complained that the star of Jordan Peele's box-office hit Get Out, Daniel Kaluuya, is not a black American, like the character he plays, but a black Brit. Jackson suggested that if Kaluuya were a black American, he might have better or more authentically expressed the condition, for a black man, of being in an interracial marriage in the US. (Jackson bizarrely believes that interracial relationships have been a walk through the park in the UK for hundreds of years.) He also took a shot at David Oyelowo, who played Martin Luther King, Jr. in Ava DuVernay’s Selma. He finally claimed that Hollywood prefers black Brits because they are cheaper and have classical training in acting.
Let's think about this for a moment.
First, Jackson can't act. Let's be clear about that. He knows nothing about acting, and so knows nothing about what a director with a heavy or challenging character faces when casting. Yes, the black Brits are not only trained in an education system that, in many respects, is better than the US's. But they are trained specifically to play black Americans. Why? Because that's where the jobs and fame are.
They are not alone.
Look at all of the white Brits and Australians who do the same thing with white American characters. Indeed, this is not even a controversial issue for them. If you are a white Brit and want work and fame, you've got to get your American accent and personalities down. But more importantly, you need training to do this, to be a convincing American. It's something you can't pick up from just watching movies and TV shows. Recall that this was the core of Mahershala Ali's speech at the Oscars. It's fine if you are going to play yourself, Samuel Jackson, but it is not so fine if you need to play someone who is not you (acting). And it takes training to play someone who is not you.
Lastly, black Americans often play black South Africans in movies. And that's cool. I personally think Morgan Freeman's Mandela in Invictus is far better than Idris Elba's Mandela: Long Walk To Freedom. The former is a black American; the latter, a black Brit.