For clarification: Their goal is actually to just decrease his victory to 70% of the votes. He's basically been unchallenged for decades and has had over 80% of the vote forever. By damaging his success by even 10%, you get to the real reason for doing this...
Not because it will solve all the world's problems, but as a demonstration of power. Showing that the movements can be organized by the internet, and they can have real world effects.
They were doing an AMA on reddit today.
Basically its a super PAC run by redditors. Their first goal is to unseat Lamar Smith.