> We must inspect your assumption that the Senate is unfair because States differ in population.
Oh we must, must we? Why's that?
It's not an assumption, but rather an assertion, based on the observed outcomes of this system in action, and the strife it has caused (literally a civil war, and gridlock in the modern era).
The assumption here is that representing states themselves is in any way a desirable goal. Just because the founders did it, does not mean that it was a good idea. Being able to observe outcomes and change your course of action when the results are not good is the mature thing to do. We do not need fetishism of the actions of people who are 200 years in the grave, the founders themselves advised against such a thing and gave mechanisms for the constitution to be changed. Unfortunately these have atrophied along with the rest of the american federal system.
States have lots of other ways to express their will: they have unitary power within their territory, they have the ability to lobby congress and the people, and they can sue if they believe their powers have been unfairly abrogated. The senate as an institution representing states directly has been dead for over a century. It is now an institution representing the people in those states already - but a very undemocratic and unfair one.
> The solution is not to remove the Senate/House combination that balances the will of people and the will of States, but for larger states to break up into smaller ones.
Which is a tacit admission that you think equality of states is a necessary and worthwhile goal to make the Senate work properly. You just disagree about how to fix the current problems with the Senate.
Sure, dividing states up to a more equal population is one way to make it work. Probably not really possible when New York City alone has the population of what, 15 or so states combined? Do you suggest fracturing the city into 15 states? That would be incredibly awful to administer.
Very simply, the Senate is just a failed design and cannot be reasonably fixed without inflicting even more cumbersome forms of government just to try and preserve it for the sake of preserving it. It needs to just be eliminated.
Not that there is any plausible means to reach any of these goals of course, Congress would not approve of states dividing themselves up since that would disadvantage Republicans. Politicians will never vote to remove their own structural advantages even when it is the democratic thing to do.