In all honesty, there are very few candidates (for president) that I (or anyone) should really trust to carry through with what they say they want to do. This is in part because they eventually discover that they can't actually affect the change they want to, but mostly because the kind of people that want power (ya know, the ones that run for office of any kind) almost always want money too, and certainly require it to actually get elected.

The following is "the system" in a nut-shell, and how to do your part to change it:

The wealthiest ~.001% control the corporations. Corporations make enough money to hire lobbyists (the middle men who meet with a given leader and negotiate how much a leader's vote is sold to the company for). Corporations send these same lobbyists to similar deals with media companies, controlling what is reported, and in what light the subjects are cast. The news media control which candidates the masses are exposed to. This means that the principle of name recognition comes into play, which means the media controls the candidates, which will inevitably decide the leadership.

The above is an A=B=C explanation of how propaganda works.

So if someone wanted to be smart about making their opinion/power count, they'd forget about "the .001%" and "the leaders" and start noticing that they themselves are guilty of funding the regime, every time the shop at Walmart, or eat at a fast-food chain, or buy a weed-killer.

TL;DR: If you want to change the world: stop buying the products, that fund the companies, that fund the lobbyists, that fund the laws you don't like.

(The above is a post I wrote in reply to a comment. After completion, it started to sound more like a post in itself, so here you are.)