On the contrary, I'll argue the partisanship is not due to the size of the nation; if it were, you could draw simple geographical lines separating the different

On the contrary, I'll argue the partisanship is not due to the size of the nation; if it were, you could draw simple geographical lines separating the different regions, and the further apart two regions are, the more likely they would belong to different parties. But that quickly becomes messy when you realize even the reddest states are 25-30% democrat, and rural areas in blue states are almost invariably republican. How do democrats (or republicans) manage such uniformity across the nation, if it is the massiveness that thwarts cohesion? Wouldn't we see states that are 100% D/R up to a rounding error? I propose that the massiveness is not spatial. It is ideological. Draw a straight dividing line in ideology space, and you can cleanly cleave US society. Project it onto a map, and it looks like a fuzzy boundary between urban and rural. But I think it's clear that the partisanship is generated by ideology and has reflections in geography, rather than the other way around. So consider federalism that isn't based on states/territories of land, but rather based on ideological space. If we used a Proportional Representation system, I might have some ideological representatives in congress. As it stands, my representatives represent their party and my physical location, but not the thoughts and ideas of voters like me.