Hire a couple people who are really good at making memes and other easy to digest content relative to your cause, then hire 1000 3rd world workers to constantly spam that content on the 10 biggest social media outlets, chat boards, etc. being sure to hit all the big groups that are in the ballpark of your cause. Amplify existing messages favorable to your cause with reposts and reactions.

Basically just a big astroturfing campaign.