Unreasonable people are not a protest's priority. They are entrenched. If they're with you, you won't lose them. If they're against you, you won't win them.
Note that this bias towards the reasonable only applies at the early stages of organization. When one is building awareness, before specific policies have been mooted. Once policy fronts develop, the unreasonable play their part. They create your battering ram of a base that focusses elected leaders on ensuring your policy remains a priority.
Putting the unreasonable front and centre too early leads to each camp preaching to its choir while the masses disengage.
Contrasted with insensitive to reason.
So no, not a dog whistle.
Able to be reasoned with?
Mainstream pertains to "ideas, attitudes or activities" [1]. A protest probably wants to appeal to those who hold mainstream views. Or bring its supporters' views into the mainstream. But the whole point of the protest is something isn't mainstream that should be.
And then on the extremes are the unreasonable people. Those who will support the police regardless of any negative change, and those who will oppose the police regardless of any positive change.
It does not purport to limit those who are reasonable. The phrasing could have been used in a dog whistle which does, but this particular remark isn't it. Moreover, there is little audience for such a dog whistle in the midst of a conversation about practical ways to effect meaningful reform.
This should not be a wedge between us that impedes us from working together towards justice and peace.
Slight edit, to target reasonable people. Period. Reasonable people can hate the NYPD. But because an overwhelming majority of New Yorkers support the NYPD, the average reasonable New Yorker is likely to as well.
Speaking to the current environment, I believe there is overlap between support for the protestors' cause and the NYPD in general.