Looks like I was wrong.
Cummings has been mob-lawyer fanatical about defending the IRS and Lois Lerner. It's pretty obvious they were trying to suppress conservative votes, and most of us wondered why Cummings was as vehement as he was.
I guessed that he was merely angling for a big reward from Obama or another Democrat president down the road -- an appointment as head of some big agency, for example. Now it looks like he may have been trying to hide his own involvement.
It came to light that Cummings was hounding the IRS to target True the Vote in 2012. The IRS complied and even gave tax info about True the Vote to Cummings. See oversight.house.gov for more details.
Just watch. Cummings will claim there was nothing unusual about this -- members of Congress make inquiries to agencies all the time. He didn't report it to the committee because it was meaningless. Besides, it was some junior staff member's fault.