Tonight, on the syndicated McLaughlin Group political talk show, Lawrence O'Donnell, senior MSNBC political analyst, claimed to know that name--and it is, according to him, top White House mastermind Karl Rove. Here is the transcript of O'Donnell's remarks: "What we're going to go to now in the next stage, when Matt Cooper's e-mails, within Time Magazine, are handed over to the grand jury, the ultimate revelation, probably within the week of who his source is.

"And I know I'm going to get pulled into the grand jury for saying this but the source of...for Matt Cooper was Karl Rove, and that will be revealed in this document dump that Time magazine's going to do with the grand jury."

It was reported on last night by Kos and others. I'll have the video up later tonight.

Talk Left goes into the legalese of the case, but suggests the reason for the Miller/Cooper actions is to make a perjury case.