How does a meme work ?
Let's say there's a new movie out and only a select few (VIPs) saw it. Maybe think Indie-movies.
Everyone else feels left out, but they don't know what they've missed.
Since knowledge is power, the ones who saw the movie now have more power, especially if the movie is really really good.
For example, I've never gotten into HBO's GOT, but I remember feeling left out, or having that "I'm not with the cool kids" kind of feeling.
A meme works the same way, but it works even better – it's not an hour long. Memes are concentrated information.
The rest of the society has no other choice but to follow the "leaders" who saw the meme. They have more knowledge, and hence more power.
Keep doing this over and over and over, and there will eventually be a tipping point where the entire country changes. Or the whole world.