Is this really the best immediate reply? To go straight for the racism accusation?
I mean, it's a defensible position. You can make the allegation. (One might ask in today's climate when such allegation
cannot be made.) But given the moniker he used was clearly over-the-top irony, silly, and half laughing at himself in using it (to mirror my point about Warren, which he thought was ridiculous), why go with the heavy gun?
I'd have replied with, "At least she's moving up, unlike Brokeahontas' poll numbers." That's awful, of course, but it's a proper return for the bad joke served.
In trying to ascertain who's a Trump voter and who's not, I surmise a lot of "shy" Trump voters may be reactionary.
Eighty percent of Americans think political correctness is a problem in this country. The Twitter culture police are only ten percent of actual Democrats. (I'm not re-citing the NYTimes article I cited for that proposition a million times last month.) I think it might be that a lot of hidden Trump voters are moderate Democrats and Republicans who react to the purity, certainty, and officiousness of call out culture. They vote against the hall monitor wagging a finger at them.
Dropping the heavy handed accusation of racism (however you define it, the majority of this country views it as a pretty strong allegation) too immediately could turn off potential votes against Trump. It's very difficult to support people who gift themselves the pedestal from which to immediately judge others, and judge those others quite harshly. On one hand, that approach is often absent much humor (which gives away one of the best approaches to actual racists, who don't know how to reply to being mocked or laughed at). On the other, it's a bit alienating ("Who's this crossing guard barking the definitions and judgments at us? What's his qualification to do so?").
Maybe rearrange responses to save the big ammunition of "misogynist" and "racist" for reply when necessary, rather than spending them early and unnecessarily, at cost of votes?
The Twitterverse of the Left, with its call out (and call out often) behavior, is going to cost the Democrat a few percentage points in 2020, and Democratic candidates going forward from there. It's just a question of how many, and in what states.