The higher Omar’s visibility the brttrr for DJT.
That’s basically it.
There was an impression that Pelosi had successfully put the Justice Dems under some sort of control, and that impression is bad for Trump.
So he comes in with this blistering attack, obviously crossing a lot of societal taboos in the way he did it. He strengthened Omar and Tlaib etc relative to Pelosi by doing it, making the internecine fighting on the Dem side more durable.
The best thing for Republicans in 2020 is for the “Justice Democrats” to be front and center on the Dem side.