Where do they find these people?

I decided not to care about the Presidential race until primaries started. That is early enough. Beginning campaigns a year and a half before the election is every bit as annoying as Christmas in July. At any rate, I'm trying to be a conscientious voter by researching the candidates and keeping tabs on the process.
Now, there is a lot that I would like to say on this issue, and I might say it later. But let's be honest--it's now 12:45 a.m. and I have an 8 a.m. class that I plan to be functional for. I just need to express one simple thing before I can sleep: how in the world do these candidates round up warehouses of supporters? Do they just make a call? "Hi Mike, this is Hillary, I'm just wondering if you could get me 4,500 beaming fans by 7 p.m. at the Kellogg plant." Mike pulls a few strings, and soon Hillary is standing before a multitude, peddling her wares. She throws in some words like "change," "progress," "comeback," promises to work indefatigably for the good of the country, claims extensive (almost presidential) political experience, and these people explode, as if on cue, with unrestrained bursts of applause. (One wonders if she promised babysitters and snowshovellers if they would only come to her rally.)

But I'm being unfair. I don't hate Hillary, and if I'm honest, the other candidates aren't so different. It's mostly pandering and political sleight-of-hand. I just dislike the way that some people choose to swallow whole the absurd rhetoric of many of these candidates. How is it that people still actually choose to accept what politicians promise at face value? One would think that we have learned.