This is not just an affront to the Constitution. It makes a cruel joke of the entire legislative process. What good is any law if the executive branch exercises what is effectively a line item veto subject to individual whim and fickleness? What good are any laws if they are subject to re-writes by a single individual or administration?
There is good reason for significant concern when we're talking Federal Law and the President but it is no less important when it strikes closer to home. We have ordinances that commonly go unenforced. We've all seen the rental sign for the basement apartment up the street though it is zoned single family residential. We have public statements regarding our otherwise entertaining urban chicken ban indicating it will be enforced only upon complaint. We have an overlay district in the village that bans neon signs yet this collage is but a few of the gaudy display available on any given day.
A law that goes unenforced is not a law and breeds contempt for other laws and those who enact them and unlike the situation with the feds here at home the executive (in)actions rewriting our ordinances do not come from an elected official. Consequently voters have even less say regarding this questionable practice.