Implement policies in the State level then? Wasn't that the original idea of United States of A?

Only 10 of your States has more people than Sweden.

Roughly 20 states has a population more than 5.5 million, which is the ballpark where Denmark, Finland and Norway are. So 30 States have less population than a typical Nordic country.

Sweden is likely more diverse than at least 15-20 of your states - a bit hard to compare due to different kind of demography statistics.

And we have free movement of workforce in EU/Schengen, so that ain't too different from US.

If there is a will, there's a way.

Democrats don't want to let individual states decide for themselves (Republicans for the most part don't want to either). They want national control over as much as they can get.

That is a political problem - totally different (and fixable if people want) than claimed issue that the Nordic model couldn't work in the US because difference in the size of population

That's part of it. The other part is that people are in favor of local control, even down to the most local level--until the local government and/or local voters (especially if it's their government and/or local voters) do something that they strongly disagree with.

>Implement policies in the State level then? Wasn't that the original idea of United States of A?

Yes, it was. That's why they had a confederation, not a union, organized under the Articles of Confederation. It was an abject failure. Nothing was able to get done because the states couldn't agree on anything, and the central government wasn't powerful enough to force them to do anything.

That's why the Constitution was invented instead.

It's a bit similar to the EU: the central government is too weak to force the members to adhere to its policies, so it's falling apart.