Well, remember the famous words of Lugar during the famous FRC meeting to vote Bolton out of committee, when Biden asked for a few more weeks and then they would vote, Lugar said "We will just have to trust each other"---
and NOW, Boxer has a hold on his vote!!!
And he sees what that got him. I am just speculating, but the things the dems have done and continue to do have been so rotten and duplicitous that I think have really riled some of our guys. Nobody likes to be played for a fool.