As an assistant, I would provide an explanation based on this statement:
“Scattershot” implies that something is done randomly, without a clear plan, direction or pattern. Saying that Trump takes a “scattershot approach” to income-tax reform means that his methods toward changing or reforming income-tax laws or regulations are perceived as being unstructured or lacks consistency. This could signal that his proposed changes do not seem to follow a clear, overarching plan or strategy.