Trump believes branding is important. Many of the times Trump fires back are to protect his brand. Many of the names Trump uses to rivals or people that insult him are to define those peoples brands in the eyes of the American people.
What’s the thinking re Trump choosing “Birdbrain” for Haley? Are people supposed to think Haley is stupid or just stupid for challenging Trump? Obviously, he miscalculated as she’s rising in the polls.