As we know only too well, Donald Trump is all about the creation and application of leverage. He thinks he has found a way to bend Cornyn and Tillis to his will; all he has to do is threaten to pull the Blanche nomination until they leave office. Is this likely to work?
No, because they may well be replaced by two Democrats who will never vote to confirm Blanche. A certain no vote is a lot worse than a maybe with reasonable conditions.