I Am (as usual) Confused

There's something strange about republican imagery and fundraising tactics that I don't quite understand. Some Republican goofball left a copy of an RNC fundraising presentation in a Florida hotel room, and now everyone can see it. The power point slide above seems to be getting the most attention, and it is rather amusing in a very weird sort of way. But I'm not sure that I 'get' the author's intention.
Okay, I can understand the "Obama as the Joker" image has some propaganda value. Rather childish, but I can see how the caricature implies "evil". The same for the "Pelosi as Cruella" image; silly, but I get the point.
Now to the parts I don't understand: Pelosi and Reid as "American Gothic"? This is supposed to imply...what? That they're like a classic portrayal of "Americana"? That they're "old"? (Not exactly a campaign tactic that helps republicans, in my opinion). That Harry Reid carries a pitchfork? This hurts them how?
And the caricature of Harry Reid as "Scooby-Doo" leaves me really confused. I'm certainly no expert on "Scooby-Doo", but I did see the cartoon in my youth. A large, goofy dog with a "snack dependency" (I always thought it was a thinly veiled drug reference) who bumbles around, but is always the "hero" by the end of the show. Correct me if I'm right, but Scooby always solves the mystery and stops the villain in the end. So is the point that Harry Reid is a clumsy hero? That he's a snack addict? My understanding of the parody is unclear. Making an analogy that Harry Reid is a "good guy" doesn't strike me as all that damning. If anything, comparing Harry to Scooby is more complimentary to him than a lot of things I might say about him; I have my doubts that he'll 'save the day' at the end of the episode.
I do understand the use of caricature in political attacks; it's a very old technique (Thomas Nast springs to mind). But this amateurish attempt is beyond feeble. Pelosi and Reid are both rather easy targets for parody in reality, but this attempt seems to completely miss the shot.
Am I missing something?