This is hardly an idea without precedent would better serve the needs of the constituents while be very much in the spirit of the Constitution. Virginia, New York and Massachusetts split and gave us a handful of other states. When states become two politically oriented in one direction for only a given geographical ares while ignoring the wishes and values of the other states they can and should split.
I'm not sure it was due to political orientation so much as the more basic "There's more people in these here hills, and we ought to have representatives for them to talk to less than a week away by horse."
That isn't to say your premise is invalid -- those people's interests are going unrepresented and splitting them off may better address those needs. But to be honest, New York and California both need to be punched in the face repeatedly by the feds, then bent over and hammered in the ass until they stop trying to force the rest of the country to acceed to their fucked up laws.