What is the goal / what do you imagine that will accomplish?
From outside looking in: There's the perspective of Red States and Blue States, the conservative South and Liberal New England, the massive pull and difference between geographies; the popular HN participant who indicates "Every idea from California is bad because it's from California".
But when I zoom in to actual states, holly mackarel - most of them are something like 53 to 47 or 42 to 53. I don't think a single state broke into 70's. Freakin' Texas was 52/46. And from what I can tell (I'm not an election geek), a high difference is as likely to be a factor of small population as true segregation.
So splitting states doesn't seem like it'd accomplish anything except tyranny of small majority - the 50-something-percent imposing dominant will onto 40-something-percent of population; and/or the same issues that we now think of national will become, or be exposed, as state and local based.
That national politics - heck, politics at large - moves things to a somewhat centrist, mollassy, laggard middle, I'm starting to realize is a feature not a defect.
Edit: Now, if you were to separate rural vs urban, you might obtain more of a result that you want; that seems to be a far more consistent predictor of average values. Whether Blue or Red state (and same for Provinces here in Great White North), it's almost universally, strongly, obviously a rural vs urban difference, and than a matter of how much population lives in urban vs rural. Sure Texas is red, but Houston, Dalas, Austin etc are blue. But I don't think that's either feasible or would accomplish any positive goal whatsoever :)