I figured, so my reply was half tongue in cheek too. 
more moderation, less free exchange
Having seen my share of well-moderated boards and boards that prefer “free exchange”, I vastly prefer the former. For one thing, a board with less moderation would have gone even worse for OP, because the thread would have immediately dissolved into pointless fighting. Who benefits from that outcome?
Moderation is needed if it means a community stays stable. From what I’ve heard, there have been some bad mods in the past, but that can apply to any community, really. The Dope, in my opinion, is a great place to hang out and exchange ideas (with some corny jokes here and there 
).
I was told/read before that one or two police requests to stay on topic or not fight the hypothetical were Okay? But if it continues - flag?
Isn’t free exchange really just code for assholes assholing?
I own my threads. Until someone else posts to one. It then become our thread.
Can be, but not exclusively.
People who like to provoke “Let’s you and him fight for my entertainment” situations for shits and giggles.
That’s what I thought as well, but the junior-modding rule is more general:
Any sort of chastisement is junior modding, even if you don’t assert authority or direct another poster. (I was recently mod-noted for chastising another poster, much to my chagrin.)
BANG BANG BANG!
“Uh…may I help you, officer?”
“We got a report of someone going off topic on a message board at this address. You know anything about that”?
What does this mean?
You wrote “police” for “polite.”
Oh. Would have been funnier if I’d quoted the post. 
Note the missing element… Chastising someone for breaking the rules.
I always understood in to be junior-modding to say something like, “You shouldn’t be saying political stuff here in FQ.” That’s basically a mod note.
You can gripe about someone though, otherwise we’d lose half the threads in the Pit. 
I refer those talking about controlling their own threads back to
From 2021. Not that it’s a controlling vote, that’s always been up to the mods. But for those that bothered to vote, we had a solid majority indicating that once you wrote the OP, you own it. Or, as @What_Exit said clearly:
I bring this up again because this is what we needed to do after our last set of mass-shooting related gun threads. Narrow focus, and pretty much asking a mod to ride cowboy on the thread more-or-less full time to keep in on track. It’s a lot of work for the mods, and I’m not sure the topic referred to in this thread is a worthy investment of the time, as it’s just not that big an issue.
For the record though, I think the best option to the OP’s problem would have been a mea culpa about a misleading question in that starting point, and tried to clean up the confusion between the clear ‘no politics’ request and the inherently political nature of the subject.
But, (final thought I promise) you’re STILL stuck with the issue that a large number of posters, including those who should know better, will respond to the question written as the title, or in the OP, without reading the rest of the thread even if you do rephrase. So, and I don’t mean this insultingly, we all have to be a bit tolerant about it. Because if I had a penny for every time I answered something, and 10-20 posts later someone repeated the answer (or submitted the same link, etc), I’d have… about a buck twenty.
ETA - breaking my own promise of final thought though, AFAIK, nothing’s stopping you from re-writing the whole OP and submitting it to the board, probably with something like (NO POLITICS) written into the new title, but I figure it’s going to be so narrow you won’t get much discussion.
Quoting myself from the thread I referenced earlier -
So in my opinion, the OP should be able to set up their question as narrowly as they want in their OP, because they are looking for a specific set of answers or debate on a specific point. This is self correcting, because if they make it too narrow the responses are going to short and too the point and likely taper off over just a few replies.
Yep. I’ve done this on many posts. On about half of them, when I was typing, "I’m not sure I explained my question clearly, let me try to be clearer, " I was thinking “These goddamned idiots, do they ever read the OP?”
But those thoughts can stay in my head just fine.
The first thread was about the established meaning of the phrase “witch hunt”. The newer thread was about what Mike Pence may have meant in his response to a question about a highly charged political situation. I can’t see the two threads as similar, but that may just be a failing on my end.
Mr. Norris, could you perhaps compose three brief examples of acceptable responses to your thread about whether or not Mike Pence was referring to himself as the preferred alternative to DJ Trump?
No, you’re right. The ‘witch hunt’ thread could have been stripped entirely of context and the discussion could still take place.
“A man says he is the sole target of a witch hunt. Is that an accurate use of the phrase?”
The Pence thread cannot be stripped of context.
“A man says he might prefer something more than something else. What did he mean?”
And the context of the statement is entirely political in nature. You can’t take it out and expect a conversation to take place beyond the possibilities mentioned upthread by Babale.
I can’t say I entirely agree. If we discuss something long enough to thoughtfully determine that it has no merit, doesn’t the process itself lend merit to it?