Considering the impact that America has on the rest of the world, and how that world generally prefers a Democrat government, it would be an interesting experience to attempt to influence the US elections. Sure, it seems like a corrupt idea, but let's face it, as far as western democracies are concerned, the US is amongst the most corrupt (gerrymander, rules to make it difficult to enrol et cetera).
So let's say that I want a say in the US elections, but not being a citizen, I can't. However, I could get a non-voter to enrol and vote for me, theoretically. If you are a non-voter, tell me how much you would sell your vote to me.