No this is a racist comment, it's more than just the "looks like a GOP convention" part. Before that he says he's going to give a list of reasons to not watch the winter games, then among that he includes the lack of black athletes and says that means the winter games don't have the best athletes in the world. That's racist, that's racist twice, first in saying we shouldn't watch the games because there's so few black, and second saying this can't be a collection of great athletes because there's so few black.
It is a racist comment and he should be called on it. First he says the athletes aren't really athletes BECAUSE THERE ARE NO BLACKS. Implication being that whites aren't capable of being elite athlets. Then he references the GOP Convention as being all white, the implication being that the GOP exludes blacks.
Wake Up.
Of course to libs like Gumbel "GOP Convention" is really a code-term for "KKK Rally."