This is an interesting question. I've just started reading the trilogy so I'm sure their is more information to come, but from what I gather it is indeed a dystopia that could work. Not all dystopias are so blessed, even those that I like. Take "Idiocracy" a film I dearly love. The theory behind the world is sound that dumb people out breed smart people so if you follow that trend you eventually reach a point where the dumb rule the earth. The problem I have is that it can't work for long. There has to be a point of maximum workable stupidity before some crisis kills off vast majority of the population. Since, it is likely that the dumber members of a society would statistically die more readily than the smart ones, the end would result would be a world where the balance between smart and dumb is naturally reset
As I said I think that the dystopia of the Huger Games can pan out for quite a while. There are several reasons I believe so. First there is the historical consideration. The government of the Hunger Games has already survived a revolution and that's daunting knowledge to those in the districts. The fact that an entire district was completely destroyed does a lot to force the other districts to cooperate. This was a tactic supposedly used by imperial China where they would burn a city to the ground for not paying taxes. The next time a city refuses to pay high taxes the collector would say, "Do you know Chow Zhen?" and the city fathers would say, "Where is Chow Zhen?" The collector would just say, "Exactly."
Taxes were paid.
The second thing to consider is that the center, wisely named the Capital, is in a highly defensible position geographically. Being in the middle of the rockies, to reach it revolutionaries would either have to use well guarded roads or try to climb some of the highest mountains in North America. Neither is a good prospect.
They also have a stranglehold on resources. Even if a district tries to stop giving to the Capital they've already hoarded enough to survive any embargo of say coal than that district can handle the stopping of food supplies. They control the districts through their bellies and that's a tough thing to beat.
They also have hoarded technology. The districts are lucky to have electricity a couple of hours a day. The capital has hover craft and access to advance genetic engineering. They have the technology to take on all 13 (now 12) districts at once.
I think the really clever thing though is that the Capital is smart enough to allow some small insurrections. There are draconian punishments for going into forbidden areas, having weapons, hunting, and the black market. Yet all of these are allowed to some degree with even the local police buying some fresh meat from time to time. This allows a bit of a safety valve, as desperate people need some hope of getting some extra food. It also acts as a fairly safe way of identifying potential trouble makers. On the darker side, if everyone is buying from the black market then everyone is a potential criminal and the police are free to arrest nearly at will a clean conscience.
So all in all, yes this scary dark future while not likely is one that could exist for many years. One hopes it never arrives of course, but it is making for an interesting book to read so far.