Interesting that our constitutions are not so different. I accept that the difference between the two societies is really more a reflection of present society, not their past.
I only meant to say that the US constitution is a unique document as it was created by a group that profoundly did not trust the organization they were creating! The nature of the document reflects that context. Norway's constitution I expect was drafted with knowledge of the US contitution, though I don't know if the USA was yet such a success that one can credit it as the model.
but in any case you are right, the present difference comes down to a difference in the populations. and those who treat the founders a prophets do look at the success of the past and strongly attribute any degredation of that success as caused by changes from the past. (not a view I subscribe to generally, but it is prevalent where I am from)