I'm not saying My Little Pony promotes communism, it's just that Lauren Faust hasn't said anything about the importance of a democratic system while her show consists of nothing but ponies working together under the rule of a single dictator with completely state-run enterprises (just look at Winter Wrap-Up).
The mayor, which Faust has not denied is merely a puppet of Celestia's tyranny, dictates the roles of each pony to clean the weather.
First of all, that's communism. Second of all, that's unnatural manipulation of Equestria's weather. I say they create more problems by engineering the environment than letting nature take its natural course. Ponies should not manipulate the weather. It's a natural cycle.
Lastly, I'd like to point out the seemingly class-based hierarchy of the pony government. Again, I'm not saying it's communist, but you see a very similar structure in a communist system. You have the dictator at top (Celestia), then the party members (unicorns), the enforcers (pegasi), then you have the lower class, the laborers, forced to work for the party (earth ponies). Again, I'm not saying it's communist, but it seems to promote some pretty un-American philosophies. It's too easy to make fun of Glenn Beck!