And, your claim argues against itself. The problem is that minds can be changed in either direction, and the people who "didn't believe in any of it" had been precondtioned to reach that position of non-support before DEI was even a thing.
Likewise, Trump was able to manipulate people based on age-old tactics or, as you put it, he "untapped" existing resistance. So how, exactly, do progressives convince these same people?
You're suggesting they do so by not moving too fast? That they wait for the "culture to be ready for change"?
If we waited for the culture to be ready, then schools in the South would still be segregated. Instead, they were integrated under the protection of men holding rifles.
Of course the status quo doesn't change without pressure. That's why it's the status quo. There is no amount of progressive pace calibration that would have addressed this. If there was, then 400 years should have been enough time.
Again, the problem is not with progressive pacing. The problem is on the other side.