Kaine was in no way part of the loop and is in no position to know.
Kaine is trying to show he is qualified to be President.
One of the jobs of the President is to read incredibly stupid lying talking points and pretend you believe them.
Mission accomplished.
I didn’t know Kaine needed a seeing eye dog.
A possible line of rebuttal to Kaine would be to tell him that the classified content in the Clinton emails under discussion didn’t start out mislabelled. The markings were deliberately stripped as part of transferring the classified content to the unclassified server. In other words, there was no administrative error here; someone and perhaps more than just a single person on the Clinton staff committed a criminal act. It is also clear that these staffers were put into this position by Clinton’s insistence on receiving all her emails on her personal email server.
Kaine would do well to remember that persisting in defending the indefensible will not mark just him as a blindly loyal soldier of the party. It will call into question his own character and integrity and raise questions about his further fitness for office.