What do you call people who make Trump a central part of their identity and constantly look for ways to work their hatred of Biden/Democrats in to every situation?
You characterize anyone who uses the phrase "Trump Derangement Syndrome" / "TDS" as an extremist? I suppose most of my friends and family are extremists then, under your definition?
When you use language like this, it dilutes the meaning of the words.
Somewhere around half of the country generally vote for the "right". A significant portion of those folks have use the TDS phrase, to point out an observable phenomenon, of certain high profile people acting in abnormal ways when reacting to Trump.
You are labeling these people "extremists"?
How would you characterize militant racist militias that are (in relatively small numbers) scattered across the country?
Would you lump these people all together under the "extremist" banner?
Or maybe there's a less inflammatory approach?
Yes, people generally have a strong reaction when talking about the sort of low-quality human being that Trump proved to be. That's not a "derangement syndrome." That's called having a sense of humanity and self-awareness.