The plan: Use horses and horse-themed cards to control the board. Ridden Down and Run 'Em Down! will allow you to boot, send home, or fight just about anybody on the board (provided your opponent isn't also playing horses!). Pistol Whip, Unprepared and Point Blank give you additional shootout control tools to make up for the relatively weak full house structure of the deck. Between Pinto and Roan you should be able to muster most of your dudes into any given shootout if it is important to do so.
What's missing: More Cheatin' Resolutions are the main thing missing here, with this deck relying more on Noon phase control. In addition this deck would benefit from more options for dudes and deeds, as well as more ways to take advantage of the horse theme. You could rebuild this to be more tightly structured and able to win shootouts, but without more unique dudes and deeds you will suffer in ability to generate influence and control.
How to expand: The Showstopper gives you Pedro and Calling The Cavalry which are very powerful tools for this deck, making it much more capable of winning (or at least surviving) shootouts at all stages of the game. The Curtain Rises gives you Maggie Harris who is an incredible starting dude for this deck, as she accelerates your game plan by turns at a time and is very cost efficient. A Grand Entrance gives you Long Strides Ranch, The Gomorra Gazette, Buckin' Billy Ballard, and Doomsday Supply, all of which are strong additions to round this deck out. Basically any set with Entrepreneur dudes, neutral dudes, or deeds on the values 5, 6, 7, or 8 will benefit this deck.
Cards from Election Day Slaughter: Ridden Down is what makes the horse theme really shine here. Jake Smiley is also an all-star, allowing this deck to have a sizable amount of influence in the starting gang while keeping costs down. Hunter Protections is a win condition here due to this decks very robust ability to protect the control points generated by that deed. Dr. Arden Gillman is not amazing in this deck, but he is a dude with influence on a value we want to be playing.
Structure: Full House (5/7 primary, 6/8 secondary) 13x 7, 11x 5, 9x 8, 8x 6