Just when you think the Internal Revenue Service can’t sink any lower in public opinion, it goes off and does something really low.

The admission by IRS officials Friday that their agency had targeted applications for tax-exempt status by nonprofit groups with “tea party” or “patriot” in their names was a stunner — and immediately triggered angry reactions from Republicans.

Senate Minority Leader Mitch McConnell (Ky.) called for a “transparent, government-wide review” to prove that “these thuggish practices are not underway at the IRS or elsewhere in the administration.” Thuggish!

The IRS, which seems to be teaching a master class on how to mishandle a crisis, put senior agency official Lois Lerner on the phone with reporters to “explain” what had happened. Not smart.

“I’m not good at math,” Lerner confessed on the call, adding that she is a lawyer, not an accountant. Still, an IRS official proclaiming her lack of math ability? Late-night comedians must be rubbing their hands together in glee.

Lerner’s comments, while eye-popping in how they misread the situation, aren’t really the issue, however. An acknowledgment by a government agency that it purposely targeted applications from conservative groups is. Lerner insisted that the flagging of certain applications was not politically motivated, but that’s unlikely to fly with outraged Republicans.

The IRS, for not understanding how quickly mistakes add up, you had the worst week in Washington. Congrats, or something.

Have a candidate for the Worst Week in Washington? E-mail Chris Cillizza at chris.cillizza@wpost.com.

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