I like the idea of Constitutionalism. Face it: the Constitution is the Contract for Services that we the People let to organization referred to as the United States Government. We have plenty of legal history regarding how Contracts are administrated by the Courts, so let's do the same with the Government.
No, the originators of the Constitution had no idea of what their national concept would become, so they kept the Constitution limited to things that would not change over time and set in place a system to allow their Constitution to be changed to reflect the changes in society. This is called the Amendment System.
The court doesn't need to guess. All it needs to do is determine: Within the Constitution or not. Simple.