The Democrat probing President Bush's decision to erase the prison sentence of a former White House aide said Sunday there is "the suspicion" the aide might have fingered others in the Bush administration if he served time.

House Judiciary Committee Chairman John Conyers spoke of "the general impression" that Bush last week commuted I. Lewis "Scooter" Libby's 2 1/2 year sentence in the CIA leak case to keep Libby quiet. Conyers, D-Mich., has scheduled a committee hearing Wednesday on the matter.

Bush contended Libby's sentence was too harsh. Libby was convicted of lying and obstructing justice in an investigation into the leak of a CIA officer's identity. The former operative said the White House was trying to discredit her husband, a critic of Bush's Iraq policy.

Conyers said the hearings would include pardons made by President Clinton, the first President Bush and possibly other past presidents. In the closing hours of his presidency, Clinton pardoned 140 people, including fugitive financier Marc Rich.

"What we have here — and I think we should put it on the table right at the beginning — is that the suspicion was that if Mr. Libby went to prison, he might further implicate other people in the White House, and that there was some kind of relationship here that does not exist in any of President Clinton's pardons, nor, according to those that we've talked to ... is that it's never existed before, ever," Conyers said in a broadcast interview Sunday.

A Republican on Conyers' committee took issue with the investigation into Bush's decision in the Libby case.

"It's clearly within the authority of the president," said Rep. Chris Cannon, R-Utah. "To go after the president on this issue shows a dearth of any opportunity to go after something substantive in this administration. I would prefer that we not waste our time in Congress on these witch hunts and frivolous activities."

A second GOP lawmaker said Bush's action in the Libby case would hold up well against Clinton's pardons. "I think we'll put up the record of the president versus the record of Bill Clinton, and the president will come out relatively good on that," said Rep. Pete Hoekstra, R-Mich.

Bush acted last Monday just hours after a federal appeals panel ruled that Libby could not delay his prison term. Libby probably would have had to report soon, which could have put new pressure on the president, who had been sidestepping calls by Libby's allies to pardon Vice President Dick Cheney's former chief of staff.

Conyers said he wants Bush to waive executive privilege and let his pardon lawyers or other experts, "who it appears that he did not consult, explain this in a little more detail. ... Commutations usually follow after a person has served some period of time. And of course, this isn't the case here."

In his commutation decision, Bush left a $250,000 fine. Libby paid the fine on Thursday.

The special prosecutor in the leak case, Patrick Fitzgerald, took issue with Bush's claim the prison term was excessive.

Sen. Charles Schumer, D-N.Y., said the Senate Judiciary Committee would "like to hear what he has to say. Obviously, he can't talk about anything that occurred in the grand jury, but there's a lot else that he might be able to tell us" in the wake of the commutation.

Conyers said his committee wants to learn more about the purpose of the commutation.

"The simple fact of the matter is, is that what separates this from President Clinton's pardons and anybody else's is that this stepped in in violation of the rules of sentencing guidelines, in which the president is not supposed to intervene until there has been the exhaustion of the appeals process," Conyers said. "And here, the president didn't wait."

Conyers appeared on "This Week" on ABC, Cannon and Hoekstra were on "FOX News Sunday," while Schumer was interviewed on "Face the Nation" on CBS.