No, you are talking about criminal law. What OP is talking about is severability, which exists so that if a judge determines Clause X violates the law, they can

No, you are talking about criminal law. What OP is talking about is severability, which exists so that if a judge determines Clause X violates the law, they can still (attempt) to enforce the rest of the contract if X can be easily remedied. I.e. The contract says no lunch breaks but CalOSHA regulations say 30 minutes required, the contractor can't violate the contract in its' entirety, they just take the breaks and amend the contract if the employer pushes it. I disagree with OP - a judge can always choose to invalidate a contract, regardless of severability. It is in there for the convenience of the parties, and I've not heard of it being used in bad faith.