You know, I was of similar opinion when reading the line, though it didn't register as sharply. It's a bold claim: to say that now, "black people lead the free world". I get the sentiment: the world in general has made a big step when Barack Obama was elected because it has shown a volume of acceptance previously unseen in one of the world's most... let's say, sharply-divided countries, opinions-wise. I'd agree without much hesitation had it said "a black man leads a free country" (even then... but hey) or "black people have the opportunity to lead the free world". I'm not trying to be racist or to pick up a fight, but I'd like to clear something up.
Just to clear things up more, in the US we call the President "The Leader of the Free World." Or at least they say that on TV all the time. We don't actually think that's the case, but it's a respectful way to refer to him to show his power and prestige.