How about Denmark? Seems like a smooth running country. Hardly any national debt. Free healthcare and education for all. Consistently rated as one of the happiest countries on earth.
Do you think that Delaware or Wyoming's economic systems are substantively different from those of the USA as a whole? Obviously, the specific industries/service sectors of these states are quite different from one another, and from other states, but they represent applications of "the American way" to very small populations (1M and 600k respectively, massively smaller than Denmark).
The Danish way of things is clearly an entirely adequate model for populations of up to 5M or so. Claims about culture, geography are red herrings (they are almost always overstated, and sometimes just outright lied about).
Whether it can scale to, say, 40M larger (as in our biggest states) is a valid question, but given the much greatest similarity between Denmark and Germany than Denmark and anywhere in the USA, despite Germany's 84M population, I'd suggest the burden of proof there is on those who say it can't scale.
Of course, the Nordic social democracies do have their own problems, and there's no shortage of people from those nations who will fill your ear with complaints. Some of them deserve to be listened to, but if you think that society is better when modelled around collective self-improvement, broad social interdependence, and a general sense of shared responsibility for everyone's welfare, they are mostly noise.
