I'd imagine the lawyers can provide some insight into more nuanced aspects of the answers, like the Defenses raised at the end of the Government's answer.
Added Note: Affirmative defenses are waived if not asserted in the answer so it is better practice to assert a colorable affirmative defense and drop it later than to lose a colorable defense that might end up being a winner.
I'll just make some general comments on the affirmative defenses. A lot of the regulars here probably already know what I explain below but here goes.
1. The Plaintiffs have failed to state a claim upon which relief may be granted.
This should be in every answer to every complaint filed. It basically means that even if the facts (not legal conclusions) in the complaint are true, they provide no basis for legal relief. This used to be called a demurrer (maybe a few states still use that term). For example, A sues B because B's purple hair makes A sick when A looks at it. Even if true, there is no legal claim.
2. The Plaintiffs have failed to set forth irreparable harm or any other basis upon which injunctive relief is available.
Injunctive relief is normally available only when compensatory damages (money) cannot remedy the harm; i.e., damage to the plaintiff cannot be repaired. An imminent threat to one's civil rights or ongoing violation of one's civil rights may form the basis to claim irreparable harm. A past violation of civil rights, especially if isolated, can usually be cured by monetary damages. In this case, the argument for injunctive relief is stronger because of the 11th Amendment (see #5 below).
3. The Plaintiffs lack standing.
A person or entity cannot normally assert a claim if they are not the person or entity being harmed. There are some exceptions for associations whose members may be harmed and some exceptions for public interest groups asserting claims of harm; e.g., environmental groups. In its simplest form, lack of standing is easy to understand. A has no standing to assert a claim against B for punching C and breaking C's nose (assuming no parental or other special relationship between A and C). However, standing is often a complex question.
Here, the defendant AG may be claiming non-residents of Washington have no standing, that the Gottlieb Trust has no standing, or something else. I'm just speculating. This is usually thrashed out in discovery or and/or on a defense motion to dismiss for failure to state a claim.
4. The Plaintiffs’ claims are not ripe for review.
This basically means the defendants have not been harmed by the law and face no real threat of harm by the law. A mere theoretical belief that one may be affected by a law in the future may not be sufficient. IMO, at least some of the plaintiffs would have standing, such as the couple who live together, have pistol licenses, and wish to share.
5. Lack of jurisdiction as to certain claims under the Eleventh Amendment.
The 11th Amendment states: "The Judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by Citizens of another State, or by Citizens or Subjects of any Foreign State."
On its face, this would seem to preclude any lawsuit in federal court against any state by a non-resident of the state sued. However, IIRC, this has been interpreted to allow suits against officers of the state (the AG) in their official capacity for injunctive relief but not money damages.
6. Certain of the Plaintiffs’ claims are barred by the doctrine of prosecutorial immunity.
If prosecutors confine themselves to the normal functions of a lawyer prosecuting a case, they have absolute immunity. If they go outside that role, they may either have only qualified immunity or no immunity. IMO, the Washington State AG is acting as an administrative agency in this instance and would not enjoy immunity from injunctive relief.
