Shirley exception/origin
The origin of the term Shirley exception appears to be this Twitter thread. We've added some formatting and headers for readability.
2018-06-06 by AlexandraErin (tip jar):
So I just saw someone wondering how liberals can cut ties with conservative friends and family members over immigration policies when most Americans (including most conservatives) support immigration reform.
I'm going to talk about what I call the Shirley Exception.
The Shirley Exception is a bit of mental sleight of hand that allows people to support a policy they profess to disagree with. It's called the Shirley Exception because... well, I mean, surely there must be exceptions, right?
Hypothetical Example
Let's imagine that in response to suspicions about overbroad use of service animal rules, a city somewhere decides to just swing the pendulum 100% in the other direction. Restaurants, public accommodations, etc., no longer have to recognize any service animals.
And in the aftermath of the change, existing rules about where animals may and may not go apply full force.
A lot of people would back the change because Obviously Some People Take Advantage. (Positing that someone, somewhere is taking advantage is a great way to get the masses on your side in our politics, sadly.)
Now if you point out the existence of a blind person or an epileptic person who has a service dog for everyday navigation of life or for life-saving purposes, the Good People who just don't want anyone to take advantage will tell you:
"No one's talking about legitimate cases."
And if you point out that the rule that they're backing would affect what they call "legitimate cases", the response will be:
"But surely there will be an exception."
Actual Examples
If you back up an anti-abortion activist to the point where they actually have to grapple with a case where the parent would 100% die delivering a 100% non-viable fetus, you'll get the same answers: "No one is talking about those cases." and "But surely there will be exceptions."
All of those studies of people in Trump Country USA who were shocked, shocked, that the kind man next door who is a good father and a great neighbor and a real part of the community was dragged away by ICE?
They all thought that surely he'd be an exception.
If you point out that the laws/policies they're talking about don't offer such exceptions and in some cases explicitly forbid them, if you say "So let's put those exceptions in writing."... well, then you're back to Surely People Will Take Advantage.
See, the people who are sure that Surely There Will Be Exceptions are very comfortable with the idea of justice being decided on a case-by-case basis. They've always had teachers, bosses, bureaucrats, even traffic cops giving them some slack for reasons of compassion and logic.
I mean, if Officer Smalltown von Cul-De-Sac could give them a warning when they were caught with recreational amounts of pot as kids because it was harmless and they Had Futures, then Surely there must be similar exceptions for everyone?
That post about "I never thought the leopards would eat my face, sobbed woman who voted for Face-Eating Leopards Party" is very true, and it goes farther than personal immunity to a very generalized and broad Just World Fallacy.
Surely, they think, surely the leopards will know to only eat the right faces, the faces that need eating, and leave alone all the faces that don't deserve that.
But if we try to lay out rules to protect faces from being eaten by leopards, people will take advantage. Best to keep it simple and count on decency and reason to rule the day.
So moderate conservatives, what we might call "everyday conservatives", the ones who don't wear MAGA hats or tea party costumes and think that Mr. Trump fella should maybe stay off of Twitter, they will vote for candidates and policies that they don't actually agree with...
...because in their mind the exact law being prescribed is just a tool in the chest, an option on the table, which they expect to be wielded fairly and judiciously. Surely no one would do anything so unreasonable as actually enforcing it as written! Not when that would be bad!
And then they are confused, shocked, and even insulted when people hold them accountable for their support of the monstrous policy.
"I didn't vote for leopards to eat your face! I just thought we needed some face-eating leopards generally. Surely you can't blame me for that!"
The old "Defense of Marriage" laws are another textbook example of this.
Many of them included language that expressly forbade giving similar benefits (like hospital visitation) to same-sex relationships.
Yet the people who voted for them, in many cases, wanted it to be known that No One Is Talking About Stopping You From Visiting Your Loved One In The Hospital. And Surely There Will Be An Exception.
Conclusion
The Shirley Exception is how people who are only mundanely monstrous, moderately monstrous, wind up supporting policies that are completely monstrous.
And when they do, they always want credit for their good intentions towards those they see as deserving, not the outcomes.
I'm describing a phenomenon here and I don't have a solution to its existence. While convincing people that laws that don't specify exceptions functionally *don't have them* might work sometimes on (ironically) a case-by-case basis, what is really needed is a broader shift.
People need to get used to thinking about the harm policies will do as a real part of the policy, not a hypothetical that Reasonable People of Good Will Can Surely Work Around.
Maybe the tack of saying, "If it was your life on the line, wouldn't you want that to be in writing?" would work. I don't know. Like I said, I don't have a solution here. This is just a thing that happens.