Has Trump had his numbers impacted by missing that debate? I don't know, but maybe too early to tell?
IMO, it won't affect iowa. He was throwing a $7 mil party across the street. It was less than week before the vote. He just didn't want to step in shit, he sat that one out.
The Saul Alinsky (republican) technique that Trump employed - lying and smearing Cruz as an illegal - WORKED. He ruined Cruz' chances of ever being president. He doesn't care about destroying the GOP or stopping hilary, it's all about his ego.