Yahoo

“It was much better to imagine men in some smokey room somewhere, made mad and cynical by privilege and power, plotting over brandy. You had to cling to this sort of image, because if you didn't then you might have to face the fact that bad things happened because ordinary people, the kind who brushed the dog and told the children bed time stories, were capable of then going out and doing horrible things to other ordinary people. It was so much easier to blame it on Them. It was bleakly depressing to think that They were Us. If it was Them, then nothing was anyone's fault. If it was Us, then what did that make Me? After all, I'm one of Us. I must be. I've certainly never thought of myself as one of Them. No one ever thinks of themselves as one of Them. We're always one of Us. It's Them that do the bad things.”
- Terry Pratchett, Jingo

No. That would be an utter disaster gor everyone involved. The Dems and Libs would literally starve to death without the conservative mid west.
Not to mention, we have been on top for so ling we have made a lot of enemies who would like nothing more than to see us crumble in the way you mention. Your split would see our shores invaded.
Then, there is the problem of its no so cut and dry as Conservative state vs Liberal state. There would be a hodge podge of fifedoms.

Not to mention any time a country splits up loke that, peacefully or not, it quickly turns into a very bloody civl war.

I think the problem lies in the fringes of the right and left. I don't care what someone labels me but I will protect myself and family at all cost and at all hazards.