Here’s what King says about Trump in the video from the link I gave you:
“he needs to reassure us on his appointments to the Supreme Court” meanwhile Trump had already issued a list which included Gorsuch and others similarly approved by strict conservative standards.
Rep Steve King of Iowa then goes on to say “It would be good for him to sit down with some people in Congress, house and senate, and ask us for our input, and then receive that input. John McCain did that eight years ago to great effect.”
You must think carefully about the timing and the context of King’s comments which were spoken in May of 2016.
King was considered to be a top voice for “real conservatives,” so he could potentially change people’s opinions easily.
It was right before the Republican Convention, when there was all kinds of talk by the deep state that Trump wouldn’t get the nomination. The expression of doubt by King was meant to have maximum impact on stopping Trump before the nomination.