I assume you’re being half-serious, but just for the sake of thinking a bit deeper on this solution...
Achieving anything remotely “amicable” in such a “splitup” would be close to impossible when one considers what and how certain resources are split up between the two parties.
Nice thought on the surface though.
IMHO, I don't think this would be much of a sticking point. For me, I'd gladly move to North Dakota. I'd rather have freedom and freedom from the do-gooders than warm weather or resources. And look at what resource-less countries such as Hong Kong, Singapore, or Japan can do. The type of people are the greatest resource. The red states would have exploding freedom and economic growth. I say give the "best" areas to the leftists. Those area will be destroyed quickly. Maybe those ruined areas will go on sale and could be regathered into the Right territory.
Pakistan and India provide in interesting YUGE-scale test case.