"...each signatory must use his or her own discretion..."
The key word is discretion. Remember, 'discretion is the better part of valor'! The dems have no valor and NO honor.
We have been f**ked by the fickle finger of fate!
Any attorney will know an "abuse of discretion" when they see it. Moreover, Graham et al. are going to be hearing so much sh** from the base in the near future that they won't dare NOT vote to go "nuclear" if there is, at this point, a filibuster of a quasi-rationale nominee.
Hell, I live in North Carolina and I'm so mad at Graham that I am thinking about volunteering against any reasonable primary challenger.