Naw. First, not many people support this. There's always some sort of fringe movement trying to split California, this is just one of a long line. There is no popular support behind it though.
Second, the rural counties are not necessary hardcore right wing. Sure, it elects hard core republicans, but that's because the primary system discourages moderates, even if the general election is 55%/45%. Even in a rural county, most of the votes are in the cities. Notice that they left San Diego and Orange counties in the new state; those are very likely to go more liberal in the future, it's what happens with urban areas. The only thing keeping San Diego leaning right is all the military contracts.
It's naive to think one can craft a better state by getting rid of people one disagrees with. It's never worked historically, and it's really only ever been accomplished with violence and authoritarian governments.