Don’t you remember when Trump brought this up, it was just as a “favor” to Cruz? He didn’t think it was an issue, in his obviously learned constitutional opinion (see: Trumpisms on separation of powers, the legislative process, spending, etc.), but he was simply recommending that it be litigated to get it out of the way. Being pals with Cruz at the time, he was just looking out for him. I imagine he is very relieved that this has been, repeatedly, a non-issue for Cruz in court.
That’s it. Trump is a liar— in Iowa.