The "other end" of the Republican party which is generally equated with people of a lower socio-economic background and one which is less intelligent, less open minded, less fact based and much more easy to manipulate. As opposed to a regular old GOP, being a RepubliBilly will become synonymous with being considered a moronic uneducated bigot. Soon more and more people will be embarrassed to claim loyalty to that end of the party for fear of being typecast as less than intelligent. Also see TeaParty and Teabaggers.
Generally a stereotype of a RepubliBilly is someone who drives a 4-wheel drive monster truck, lives in a trailer park, flies the confederate flag, still listens to Lee Greenwood 8 tracks, and still considers it OK to display a concrete lawn ornament depicting a black jockey. One of the pre-requisites is that he must be a compulsive viewer of political commentary on the Fox News Channel and parrot it incessantly.