"Some of the judges say is they feel they've participated in a Potemkin court."

A federal judge has resigned from his position on the Foreign Intelligence Surveillance Court:

[U.S. District Judge James] Robertson indicated privately to colleagues in recent conversations that he was concerned that information gained from warrantless NSA surveillance could have then been used to obtain FISA warrants. FISA court Presiding Judge Colleen Kollar-Kotelly, who had been briefed on the spying program by the administration, raised the same concern in 2004 and insisted that the Justice Department certify in writing that it was not occurring.

"They just don't know if the product of wiretaps were used for FISA warrants -- to kind of cleanse the information," said one source, who spoke on the condition of anonymity because of the classified nature of the FISA warrants. "What I've heard some of the judges say is they feel they've participated in a Potemkin court."

Robertson is considered a liberal judge who has often ruled against the Bush administration's assertions of broad powers in the terrorism fight, most notably in Hamdan v. Rumsfeld . Robertson held in that case that the Pentagon's military commissions for prosecuting terrorism suspects at Guantanamo Bay, Cuba, were illegal and stacked against the detainees.

Some FISA judges said they were saddened by the news of Robertson's resignation and want to hear more about the president's program.

"I guess that's a decision he's made and I respect him," said Judge George P. Kazen, another FISA judge. "But it's just too quick for me to say I've got it all figured out."

The resignation seems to speak loudly, but what does it say? The resignation letter itself gives no reason. An anonymous source offers some context. The judge may see the process that he participates in as tainted and feel that he can therefore no longer be part of it. The judge may simply object to the procedure and feel that the resignation is an effective way to express that objection. That objection may be political opposition to the President, purely legal opinion, or some mix of the two. To the extent that it is legal opinion, it may not be an opinion that most judges, handling a fully briefed and argued case, would agree with. The one judge we see making a statement to the press without asking for anonymity says that it's too soon to have figured out such a complicated legal question. That sounds about right to me.