From a Wall Street Journal column by William McGurn:

The advantage of making the tax fight an argument about growth (as opposed to focusing on the tax relief) is that it dovetails with other Republican initiatives, especially the liberation of American know-how and possibility through deregulation.

Here’s something else. A prosperity-based argument would also help Mr. Trump appeal beyond his white working-class base. In his book “Coming Apart,” political scientist Charles Murray notes that the dysfunctions associated with poor black populations in inner cities — bad schools, broken families, government dependency, lack of economic opportunity — also characterize many poor white communities.

The flip side of the Murray argument is this: Measures that would open opportunities for the white working class would likely help lift others in the same economic boat. Is it any coincidence, for example, that when Joel Kotkin’s Center for Opportunity Urbanism looked to the cities where African-Americans are doing best economically, it’s not the progressive North that dominates. It’s the growing South.