They did look into it in Klaymman's case. The letter said there was no evidence of criminal wrongdoing on the part of the IRS.
But because the results aren't what Klaymman wants, we are to now assume that Ashcroft and others are corrupt. Why can't it be that the audit was based on legitimate questions?
Klayman never stated in the press release that Ashcroft and the rest of the Justice Department is corrupt. He is merely questioning their lack of concern in these matters.