1. Trump gave the "journalist" as good as he got, with ganache on top.
2. Trump humorously pointing out that Kammie was an Indian activist until figuring out that identifying as black was politically more advantageous hit a nerve at the black journalists conference (which Kammie, apparently, skipped) and also got some laughs. Kammie won't be a unifier of blacks. Many blacks - a minority, I'm sure - are tired of being exploited by the Dems and are less than impressed by Kammie being 1/128th or 1/256th black (they might even realize that this % was due to a white slave owner making the beast with two backs with a black slave who may or may not have consented). 25% or 30% of black voters voting for Trump or even voting for Snoopy would be a serious hurt for Kammie.