In comments there were some questions raised about Illinois’s resources. Unknown to most people Illinois does produce oil and refines oil. It also mines coal. It still produces iron and steel. Unlike many states it could be self-sustaining. That would be a very different Illinois than the present one.
The states are all interdependent. As I documented in comments, some states draw directly on the rest more than others. I don’t think it’s a coincidence that the states that are heavily subsidized directly by the rest tend to be gaining population while those that aren’t subsidized directly as much tend to be losing population.
My own view is that states like California, Florida, and Texas need to be spending a lot more on disaster preparedness than they are at present. I mind subsidizing very poor states like, say, Mississippi less than I do subsidizing rich states like California. Heading off a possible retort California is both the richest and the poorest state in the Union. It has more billionaires than any other state but it also has more poor people than any other state.
BTW there are states both Red and Blue, e.g. West Virginia and Vermont, that have no billionaires.