Lerner is guilty. She is obviously a corrupt stooge. But this is really pretty dang important.
The IRS fought (and is still fighting) this so hard because the stakes are extremely high. They know for a fact that “sunlight” in this case will discredit them and/or put them in prison. It very much threatens Obama, their boyfriend. It also is an existential threat to the IRS itself.
So the IRS has stalled for four years. Think about that for a second–four years. The IRS is putting a TON of effort and energy into this for a good reason. They are fighting tooth-and-nail because this is a very real threat to them. They are guilty as Hell, and “sunlight” shows their perfidy.