So there's a lot more to that than just ports and financial centers growing up where ports are, and more than I've mentioned.

Sure - but I think the larger point still stands.

Massachusetts has always been a fairly wealthy state. Oklahoma has always been a relatively poor state. Oklahoma probably isn't poorer than Massachusetts because it has voted for Republicans in the last couple of decades. It was much poorer than Massachusetts before it started voting for the GOP.

There's lots of reasons why that's the case that go beyond just ports and financial centers, but I don't think that was what Dope was really trying to get at. I think the larger point is that the correlation between wealth and "blue" politics isn't necessarily (or even likely) due to causation. The poorer states in the country were poor long before the "Solid South" broke up and turned Republican.