I don’t see that as problematic at all. Cruz doesn’t want us talking about that all the time; Trump DOES. Even though Trump HIMSELF said Cruz was a Natural Born Citizen, now that Cruz is doing so well, Trump is putting doubts in people’s minds. DIRTY POLITICS by Trump.
However, Trump does not, and never has, claimed to be a expert on the Constitution, nor is he a lawyer, Constitutional or otherwise. Cruz does make that claim. When Cruze does deign to speak on the topic, he has said it’s “settled law”. Well that came, of course after he said he’d “leave the legal consequences up to others to worry about.”
In fact he first claimed, in 2013, that he DIDN’T KNOW he had Canadian citizenship. Didn’t know? How on earth could he not know? He is an attorney, right? He had his Canadian birth certificate. And there is the Princeton collage friend that Ted discussed his dual-citizenship with. That friend went on record with the story that Ted declared as a dual citizen at the Canadian border on one visit the friends took into Canada. Ted had never refuted that story. So none of this adds up in a straight line.