Graham has always been an @ss. This is nothing new.Grudgingly, and with conditions that seem to exist only in his head. Maybe someone took him aside and told him he has a s*** hand. He likes to grandstand. He got hystericallyl weepy during the Ketanji Brown Jackson hearing, so he enjoys a good spectacle.
Those folks are going to have to answer the subpoena. They can plead the 5th, but not showing up, or claiming some imaginary protection isn't going to happen.