It’s a political axiom that you cannot let stand negative comments against you that might gain traction. It’s exactly what Bush-41 refused to do, to his own detriment.
Trump is actually handling each attack against him on its own merit, or lack of same from his perspective. He’s fought back publicly against Rove, Seinfeld and now DeNiro.
On the other hand, Trump personally called Krauthammer to make his case.
No amount of persuasion would change the thinking (such as it is) with the 2 entertainers. They and their fellow celebrities are on notice that they can say what they will, but their comments will not go unchallenged.
On the other hand, Krauthammer is intelligent enough to at least reconsider when a rational argument is put before him. Trump showed respect for Krauthammer. Why would he show respect for the others? After all, DeNiro is NOT the brightest bulb.
I look forward to each Trump response...:)