John Kerry (search) said the White House is committing character assassination with its treatment of former counterterror chief Richard Clarke (search) to avoid responding to questions about national security that Clarke raised.
"I don't think people want questions about character; I think they want questions about our security to be answered," Kerry said Saturday. "That's what this is about."
Kerry also said Condoleezza Rice (search), President Bush's national security adviser, should testify in public before the commission investigating the Sept. 11, 2001, terror attacks.
"If Condoleezza Rice can find time to do '60 Minutes' on television before the American people, she ought to find 60 minutes to speak to the commission under oath," Kerry told reporters. "We're talking about the security of our country."
The White House has said that presidential staff advisers, such as Rice, cannot testify publicly before congressional bodies. The bipartisan, independent commission was created in 2002 by congressional legislation and Bush's signature.
Rice has been interviewed privately by commission members.
Bush campaign spokeswoman Nicolle Devenish said Kerry and other Democrats are trying to politicize the work of the commission.
"John Kerry seeks to distract Americans from his own failed ideas for protecting America from future attacks," she said in a statement. "John Kerry's backward-looking approach would return us to the failed policies of treating terror as a law-enforcement matter."
Kerry said the constitutional separation of powers could be protected despite the White House's objections.
"Certainly we can find a way to respect executive privilege (search), not to have it be an opening to the door, but nevertheless to accomplish America's needs to protect the security of our country," he said.
On Clarke, Kerry said: "Every time somebody comes up and says something that this White House doesn't like, they don't answer the questions about it or show you the truth about it. They go into character assassination mode."
Besides Clarke, Kerry cited the examples of former Treasury Secretary Paul O'Neill (search) and Medicare accountant Richard Foster.
O'Neill was fired as Treasury secretary in December 2002 after publicly questioning the need for additional tax cuts, a core campaign issue for Bush. Foster said he was prohibited by his superiors from sharing with Congress a much higher but more accurate cost estimate for the administration's Medicare program.
Kerry said until the commission completes its report, he will comment neither on Clarke's testimony nor on whether Bush did enough to protect Americans before the attacks. Kerry, who spent much of the past week on vacation in Idaho, said he had not heard or read any of the testimony before the commission.
He nevertheless criticized the administration for having "stonewalled" the investigation. Bush originally opposed the panel's creation, then opposed its request for a two-month extension of its work, but eventually relented on both counts.