What determines Whether something is "Constitutional" in the USA ?

That’s fine, but I wasn’t trying to hijack the thread. I believe that the ultimate Constitutionality of a law can be determined by an individual’s conscience, and that determination can be acted through on jury nullification. It was a perfectly valid discussion regarding the OP.

Btw, I can’t find a thread where we debated jury nullification before - do you happen to remember what the title was, or was it lost in the great server switch?

One my pet peeves: people telling other people what they mean.

There is big difference between whose opinion matters as a practical matter, and which opinion is correct. I may think someone is guilty or innocent, but it is the jury’s opinion that matters. That doesn’t mean that the jury actually is correct. It is possible for a jury to find someone guilty, when that person is innocent, just as it is possible for the Supreme Court to decide a question of constitutionality incorrectly.

Now, if you wish to base your opinions regarding constitutionality solely on the basis of what the Supreme Court says, that is valid. But it is not valid to insist that everyone else do so.

If the judicial system is immoral, then it deserves to be undermined.

That’s ridiculous. Everyone has the obligation to evaluate laws’ morality. A person who claims to have as much right as anyone else to decide what is moral is not putting himself above everyone else; he is putting himself on the same level. It is people like you, who claim that certain groups have rights not shared by others, that are putting some people above others.

To address the specific example in the OP, I think a point is being missed here. The Supreme Court is not likely to say that the phrase “under God” is constitutional on its face. They are likely to say that it is a de minimus violation and therefore allow it to remain because they can’t be troubled to waste their time on such trivialities. (Although I don’t understand why they would agree to hear a case on trivialities in the first place.) Or, as with IGWT, they may say that since the phrase has been around for quite a while, its use has become secular and is not “religious”.

I don’t agree with this reasoning, but the point is that they are not likely to give carte blanche to have “under God” inserted into every government document and proclamation.