Just because a politician is willing to use a racist dog whistle when he needs to distract (Mexican rapists, judges, "good people" among white supremecists, Britain comments) doesn't mean everything he does is based on promoting the interests of one race over another.
In January, Trump was commencing his media war, the wall was going nowhere, he was upset that Hillary won the popular vote, he was unhappy that Russiagate made him seem illegitimate .... he was swinging like a punch drunk old fat guy. And he connecting with one haymaker. It was merely the first of his wild swings, and he appears to have connected with the Kapernick thing.