In a textbook, it would be called "equivocation".
> where the debater conflates two topics
Yep.
I continue to be somewhat disturbed by the fact that giving a new name to a problem we've recognized for thousands of years has apparently increased awareness. Did people not realize equivocation was bad before Scott Alexander?
Motte-and-bailey isn't just an argumentative form, it's also a political strategy. It's people pushing/doing controversial thing A but every time they get called on it they bring up uncontroversial thing B. Or, they even retreat to thing B, but then when the pressure is off they come back out and start pushing/doing thing A again.
"Equivocation" covers a wide variety of situations, but motte-and-bailey is more specific and includes the notions of a strategy executed over time which includes action.
The relationship between the two words is akin to the one between “rectangle” and “square”.
Engaging in a genocidal action and then claiming it's self defense when scrutinized is a textbook motte and bailey fallacy. Claiming that people who oppose said genocide are supporters of fringe radical elements within the genocided, is a false equivocation, but not a motte and bailey fallacy. Indeed, you could make your exact argument about association fallacies, or a wide array of other fallacies for that matter - as most tend to involve false equivocation at some point.