So who do you propose should actually CONDUCT the investigation into what has happened / is happening with the guns, if Holder isn't going to be allowed to do it?!
I mean, there is such a thing as cutting off your own nose to spite your face. Let him do his job, or get an interim. Messing with him really isn't an option.
So it's circular - we really are (IMO) back to, is it a legitimate subpoena? No, it's not.
...Unless they have some REAL dirt on Holder, that would allow them to simply remove him. I am assuming the whistleblowers would have produced it if they had it, but Holder was too high up in the food chain to be involved in this. They weren't even discussing it with ATF supervision, so I can easily believe that the Big Guy way over the Justice Dept didn't know until it was DONE and that guy was dead. He may have known about the Fast and Furious operation that Janet Reno set up, but not what the employees had turned it into after she left. What needs to be nailed is the insubordination which might actually have been compensated insubordination IOW corruption.