Matt K. Lewis at the Daily Caller:

The saga over who leaked the IRS documents continues…

In a letter to IRS Commissioner Douglas H. Shulman, U.S. Senator Orrin Hatch (R-Utah), Ranking Member of the Senate Finance Committee, has requested an investigation into the unauthorized disclosure of the National Organization for Marriage’s (NOM) confidential donor information.

Hatch notes in the letter that “evidence suggests that the IRS may have been the source of the unauthorized disclosure of donor information,” and adds that this “is a matter that I take with the utmost seriousness, and I expect that you will treat this inquiry with the attention that it deserves.”

“Our political history shows the absolute necessity of maintaining the nonpartisan integrity of the IRS,” he writes, adding: “The proper administration of the nation’s tax laws requires confidence that the personal and confidential information filed with IRS will not be improperly disclosed or used for political purposes.”

... The letter from Hatch is significant because it is the first time a U.S. lawmaker has echoed NOM’s calls for an IRS investigation into the alleged leak.

Hatch has asked to hear back from the IRS by no later than May 29, 2012. A copy of his letter was also sent to the Attorney General.