Well, not optimistic that the moderators or the RNC will allow that question to be asked and it is quite clear that the nominees thus far will not be interested in being asked the question and, if they were, would never say yes. Look at what Pence said about Trump when he announced yesterday. The candidates whole raison d’etre is to get rid of Trump and to memory hole all of the illegal things they/the government has done.
They should be forced to answer the questions if not at a debate then at campaign events