To give an extreme counter-example, imagine you had a constitution that legally gives unlimited supreme powers to a single person (which has happened, e.g. Germany during the Nazi years).

I wouldn't describe that as the rule of law, but rather as despotism. I think you can have a constitutional system that has powers codified that still violate the goals and ideals of the rule of law, without being technically illegal. It's not a black and white thing.

Does that make sense?