I pretty much agree with that, though I am not sure how current law would be affected by a requirement to carry an ID card. I am not sure what left wing lawyers would dream up to prevent the gubmint from requiring it. I can see some battles being fought over it. Is it a violation of liberty to be required to show identification under ANY circumstances, or just some?
If Situation X is a situation where, currently, one would not have their ID checked, but under the National ID system, they would, then a liberty has been violated. Namely: the liberty to be a human being in Situation X without being in possession of a plastic card.
Fair enough? :)
In other words, the answer to your question is, "Just some circumstances would be enough."
I do hope you are right though that left-wing lawyers would resist the National ID Card requirements on liberty grounds. If Dershowitz is any example, however, I won't hold my breath. Best,