Samuel Arbesman offers us the “city states of America”, a map of states that have over half of their population living in a single metropolitan statistical area:
I think this is mostly a glance at how poorly designed our currently political boundaries are. The definition of a metropolitan area is bound to be somewhat arbitrary around the margin, but these are real social and economic phenomena. But we make important political decisions at the state level. That’s not just state government, it’s senators and the electoral college as well. Some states—California, Texas, Florida—are way too big and encompass multiple major metro areas. Then you get things like Philadelphia. Six million people live in this metropolitan area, more than live in most states. But there’s no state government where their interests dominate. Instead they’re divided between the NYC-focused state of New Jersey and Pennsylvania, which is too big to have a focal point. There’s a huge continuous swath of land in Nebraska, South Dakota, North Dakota, Montana, and Wyoming that gets ten senators and has fewer residents than the Detroit MSA which doesn’t even get to dominate a single state.
Something worth noting is that while overrepresentation of low population states was obviously part of the original constitutional bargain for a reason, this is a different phenomenon. Late 18th century America was such an overwhelmingly rural country that the whole question would have been irrelevant. Meanwhile, some of the metro-dominated states are also low-population states.