For those who erupt, twitter-style, with outrage every time Donald says something obnoxious, you simply dilute the capacity to challenge him over time. You can call his supporters every identity-politics name in the book, but just like the girl crying wolf, soon those accusations will be diluted so as to become meaningless.
Do you think his supporters are chastened when you call them racist for the 10,000th time? Specifically for the word racist, I see accusations thrown around so much these days that I simply shrug now when I see them. If your go-to move is to accuse of racism, you've already lost. RIGHTEOUS OUTRAGE doesn't accomplish anything.
Also, rushing to the defense of Omar without knowing where she has stood on issues is a bad call. Trump is successfully baiting the left into strengthening the divisions within the democratic party, and forcing the demos to cement their support for Omar and AOC. The left is filled with suckers apparently. Omar has said despicable things and I will want to see her develop, for years, on the national stage before she gets even one ounce of my support. I'll choose Pelosi 1000X before any of these clowns calling themselves "the squad".
The democrats are so committed to the false idols of identity politics and balkanization through multiculturalism that they are losing the battle to frame the election.
Reparations, forced busing, Omar-as-exemplar, identity politics, these are all election-losing positions that the democrats are too stupid to avoid.