At the request of a Democratic Senate, the Bush administration in 2006 opened a rare window on the process for preparing a Supreme Court nominee for a confirmation hearing. The administration produced a list of 38 people -- members of the Republican legal elite, from inside and outside government -- who had helped Samuel Alito Jr. practice the answers he would give to the Senate Judiciary Committee.

Don't expect a similar list this time around.

The Obama administration says it won't name those who participated in practice sessions with its nominee, Sonia Sotomayor, refusing even to give a clear reason for keeping the information hidden. Republicans haven't pressed the White House to release a list, and the Democrat who procured Alito's said he's not interested in Sotomayor's.

The practice sessions -- nicknamed "murder boards" for their intensity -- typically last for hours at time. Constitutional scholars and other lawyers pose as senators, giving the nominee an idea of what questions to expect and a chance to try out some answers. The nomination of then-White House Counsel Harriet Miers failed in 2005 in part because she performed poorly in practice sessions.

But the sessions also help identify which law firms, interest groups and academics hold the most sway with an administration because only a handful of lawyers from outside government participate. Alito's helpers included former Solicitor General Theodore Olson, a partner at Gibson, Dunn & Crutcher; Michael Carvin, a partner at Jones Day; and Benjamin Powell, then an associate White House counsel whom Sen. Russ Feingold, D-Wis., targeted for his advice on intelligence matters.

The sessions are a privilege for the participants too. They offer a rare opportunity to meet with and assist a likely future justice on the Supreme Court.

Ben LaBolt, a spokesman for the Obama White House, wrote in an e-mail that it "won't be possible" to release a list of those who worked with Sotomayor. Pressed for a reason, LaBolt replied: "Fly-on-the-wall stories aren't our style."

Feingold, a member of the Judiciary Committee, asked for and received a list of those who helped prepare Alito in 2005 and early 2006. He raised the issue further when he had the chance to question Alito.

"I'm going to say that I am still somewhat troubled by the idea that you were prepared for this hearing by some lawyers who were very much involved in promoting the purported legal justification for the NSA wiretapping program," said Feingold, a critic of warrantless wiretapping conducted by the National Security Agency.

Feingold questioned, in particular, the involvement of Miers and Powell, who he said were involved in advising President George W. Bush on wiretapping. At the time, it was clear that Alito might have to rule on the legality of the wiretapping program if he were confirmed to the Supreme Court -- forcing him to weigh in on legal justifications authored by those who helped put him on the Court. "I'm just going to continue to think about this issue," Feingold told Alito. "And I hope that you and the department will, too. I think you would agree that at some point, in a situation like this, an ethical issue could arise."

A spokesman for Feingold said the senator did not ask about participants in Sotomayor's practice sessions because "there was no similar situation in this instance." It is possible, though, that Sotomayor would also end up hearing cases on issues that the White House lawyers who advised her provided guidance on.

A spokesman for Republicans on the Judiciary Committee said he was not aware of any GOP senators who had asked the White House for a list of participants in the practice sessions.

This article first appeared on The BLT: The Blog of Legal Times.