Today Senator Minority Leader Mitch McConnell discussed at length NOM's situation on the floor of the U.S. Senate and says it merits investigation:
...“Last May, Senator Hatch — the top Republican on the Finance Committee — sent a letter to the IRS inquiring about reports that someone at the IRS had leaked confidential donor information from NOM to an advocacy group whose political goals were in direct conflict with its own.
“NOM has since released documents suggesting that this information came from one source — from within the IRS itself. All this took place, by the way, in the middle of a national political campaign.
“Significantly, one of the NOM donors whose name was leaked was none other than Mitt Romney. What a coincidence. And what about the group it was leaked to?
“Well, it was headed by a guy who was named a co-chair of the Obama campaign, and who published the confidential donor information on the website of the organization he ran – an organization opposed to the goals of NOM.
“So here’s another situation that, at the very least, clearly merits investigation. There are allegations here that someone at the IRS committed a very serious crime that had the effect of chilling the speech of a political organization that happened to be on the wrong side of the current Administration.
“Yet, a year later, Senator Hatch has yet to hear anything back from the IRS. And, according to the folks at NOM, neither have they."
You can read his entire set of remarks here.