What I read between the lines is that McConnell places a huge priority on judges - he sees POTUS as a once-in-a-lifetime opportunity to get rid of liberal judges.
By calling Don Jr in to testify he is throwing Warner and some other key Democrats a bone, allowing them to save face, giving them a token win, s in order to preserve a working relationship that has allowed him to make miraculous progress in reforming the courts.
Thats what I think he was trying to explain on Hannity. If Im right about this, POTUS will back off and let Don Jr testify - he may continue to tweet that its unfair, but he wont make a federal case out of it. The committee will agree that JR did nothing wrong and the Democrat leaders will have saved face.
I say trust McConnell on this one. Its a Trump friendly committee and Don Jr is too smart to get caught in a perjury trap anyway. Then McConnell can continue to confirm Trumps judge picks and to block all the socialist nonsense coming from the House.
It is really impressive what McConnell is doing considering how thin the GOP majority is in the Senate, and considering the House us under Dem control. Give him some leeway to offer the Dems token wins here and there - thats how politics works. Then when Republicans take the House back in 2020, well be sitting pretty.
That is EVIL!!! Trump Jr. is NOT A BONE to be thrown to the Democrats for Judges!! GOOD GOD!