You may have heard that in the upcoming Thor film the very black actor Idris Elba will play the Norse god Heimdall. (Apparently Flavor Flav's silly Viking cap wasn't just part of a minstrel show. In reality he was laying the subliminal groundwork for a more subversive objective).
Of course, there are some racists who are objecting to the casting decision but (even apart from the basic fact that racism is stupid) if you actually read the comic books there are some interesting reasons to support the unconventional casting.
First of all, the "gods" of Asgard aren't human in the first place so you can't really argue that they are really white or black. In fact, in some parts of the Marvel mulitverse, (the Earth X continuity) the Asgardians are shapeshifting extraterrestrials whose forms change with the perception of others. Secondly, in Marvel Comics' Lost Gods storyline the gods of Asgard are given human identities and in Heimdall's case, he became a Latino man named Donald Velez. Thirdly, in a more recent storyline, after Asgard is destroyed in Ragnarok, Heimdall takes on the form of a Katrina survivor named Ezra. (both personas lost their homes in cataclysmic ways). In any case, the bottom line is based on the comics, the idea of a black Heimdall actually isn't so strange.
Racialicious: Thor Losers: ‘Christian’ Group Aghast At Idris Elba’s Godliness
Guardian: White supremacists urge Thor boycott over casting of black actor as Norse god
The Root: White Supremacist Group Boycotting 'Thor' Because of Elba Casting
