(Completely stepping over the fact that so much of the books was about race, and that has been removed from the films.)
Panem is a futuristic North America, not a futuristic USA. North America is actually made up of 23 states and territories, but most of those get divided into regional blocks like Central America and the Caribbean. North America is more commonly associated with just Canada, the USA, and Mexico, so we’ll assume that those three are the ones that turn into Panem. Going off basic current population stats at least a quarter of the characters should be Mexican. More than that, really, because that’s just based off of the population of Mexico, and doesn’t count Mexican Americans in the US or Canada. The combined populations of Canada and the US are over 25% People of Color (anyone not white). Add that to the population of Mexico and North America is about 45% PoC. That’s just 55% white. The casting of the Hunger Games films should reflect this. It simply doesn’t make logical sense not to.
The casting of the tributes was relatively diverse for the first film. 8 out of 24 (one third) of the tributes were PoC. Don’t celebrate too quickly, though, only two made it past the initial bloodbath, so most of the Arena scenes were filled with white people. So far seven new actors have been cast for Catching Fire; 6 white, 1 PoC. Add in Katniss and Peeta and we already have 1/3 of the victors/tributes cast. This time, though, so far there is just 1 person of color to 7 white people. That’s 12.5% if you were wondering.
In conclusion: These films are racist. And it breaks my heart.
(Source: Wikipedia, Google, and this handy percentage calculator.)
Or maybe the Hunger Games is actually a brilliant commentary on white privilege in the post apocalyptic future. Perhaps the films are trying to demonstrate how, in light of a huge natural disaster, white people will disproportionately survive and then throw all the black folks into a plantation-like District 11 that replicates the antebellum south. Then these white folks will oppress other white folks, and start a rebellion that only white people/actors seem to play a significant part in! The films are just a brilliant commentary of the centrality on whiteness!