WASHINGTON — Utah native Kyle Sampson resigned as chief of staff to Attorney General Alberto Gonzales because he had let his boss down and not because he had misled anyone in the firing of eight federal prosecutors, Sampson's attorney said Thursday.

In a statement e-mailed to the Deseret Morning News, attorney Brad Berenson said his client let down Gonzales by "failing to appreciate the need for and organize a more effective response to the unfounded accusations that the replacements were improper."

"Kyle did not resign because he had misled anyone at the Justice Department or withheld information concerning the replacement of the U.S. attorneys," Berenson said.

But Democrats in Congress contend they were misled about the involvement of the White House in the firings of eight U.S. attorneys earlier this year and have launched an investigation into the matter.

Sen. Orrin Hatch also came to Sampson's defense Thursday, calling the former staffer an "honorable person" who had an unenviable job of handling a politically sensitive task.

Hatch's comments came at a meeting of the Senate Judiciary Committee, where he accused Democrats of being "premature" in their decision to authorize subpoenas to White House officials over the firing of the attorneys.

By voice vote, the Senate committee approved the authorization for White House Deputy Chief of Staff Karl Rove, former White House counsel Harriet Miers and her former deputy, William Kelley, a day after the House Judiciary Committee authorized a similar power to Chairman John Conyers, D-Mich.

"If you want subpoena power in the chairman, you've got the power to do it," Hatch said at the hearing to the Democrats, according to a transcript. "You're all here. You know how to do it. And there's not a doggone lot we can do about it, except other than to say it's premature under the circumstances with this very, very comprehensive letter from the White House Counsel's Office."

White House Counsel Fred Fielding sent a letter to Congress offering Rove and Miers to talk with select lawmakers in private interviews — not under oath and no transcript — on the U.S. attorney issue along with offering more e-mails and other documents showing conversations that took place between the White House and the Justice Department or the White House and third parties before the administration fired the U.S. attorneys.

But Democrats have balked at the offer. Conyers and House Subcommittee on Commercial and Administrative Law Chairwoman Linda Sanchez, D-Calif., sent a letter to the White House Thursday rejecting it because the offer "will not facilitate a full and fair inquiry."

"We would not be pursuing this matter absent the evidence of misconduct, misstatements and potential criminal wrongdoing that has already come to light," Conyers and Sanchez wrote. "Among other things, the Department of Justice itself has acknowledged that its officials have misled Congress, with the Chief of Staff to the Attorney General resigning over his role in the matter."