I don’t get it. If you are the President, surely, you have the power to know with certainty. You are in charge of the organizations which would have been responsible! Just have them produce the evidence. And if they can’t, then maybe there are huge problems in the executive. Or maybe the wiretapping was legal, in which case someone managed to convince a judge to authorize it, and you were(are?) the target of a criminal investigation, but you probably wouldn’t want to advertise it like that. Or maybe there was no wiretapping, and you are a conspiracy theory loving buffoon.