Courts are supposed to construe legislation in a way to hold it valid, if possible, right? I think I remember that was sort of the default in terms of separation of powers. So it seems to me that would also lead to a Court saving parts of a legislation if those parts are salvageable.
My point on severability comes from Atty Gen. Cuccinelli. His point was if the law does not contain a severability clause (like most contracts do), then the court cannot, as a matter of law, "save parts of the law." If it does contain that, then you are right, it gets treated like the AZ law just did. The court has to parse it and see what parts to strike and what parts are retained.
So, that's his opinion, I don't really have an independent basis for saying one way or the other. I haven't done independent research on that point of law.
A severability clause is like belts and suspenders. It is a clear expression of legislative intent to the effect that a legislature affirmatively wishes to preserve as much of their act as possible should a court later find a part or parts to be Constitutionally invalid.
However, as a general rule, Courts will not rule on the constitutionality of an entire act when asked to consider only a portion of it. And general principles of Judicial restraint normally require that a ruling be as limited as necessary to address the actual case or controversy.
Now all of that ^ is pretty much from memory and I am not about to engage in a whole lot of legal research, to be candid here. But, I did come across this which is pretty much right on point:
Unless it is evident that the Legislature would not have enacted those provisions which are within its power, independently of that which is not, the invalid part may be dropped if what is left is fully operative as a law.
Alaska Airlines, Inc. v.
Brock, 480 U.S. 678, 684 (1987) (quoting
Buckley v.
Valeo, 424 U.S. 1, 108 (1976)).
