Dubya “ignored” all the lies, insults and trolling for 8 years. He had too much respect for the presidency. He was advised that he was “above that.”
He left the WH with a 28% approval. Mostly because he refused to use the bully pulpit to take on his adversaries.
Trump is light years ahead of GWB when it comes to being “above that”. In this case, Trump needs to ignore Cuban and stay above the fray.