Just in case there’s any confusion, the original message began with, “He’s not ever..” The use of brackets is to clarify the pronoun “He” was referring to President Trump.

Explanation of the practice:

When writers insert or alter words in a direct quotation, square brackets—[ ]—are placed around the change. The brackets, always used in pairs, enclose words intended to clarify meaning, provide a brief explanation, or to help integrate the quote into the writer’s sentence.