John Kerry (search) on Sunday accused President Bush of "stonewalling" separate inquiries into the events leading up to the Sept. 11, 2001, terrorists attacks, as well as into the intelligence that suggested Saddam Hussein (search) was hiding weapons of mass destruction in Iraq.

Kerry, the presumptive Democratic presidential nominee, endorsed complaints by some members of a federal commission investigating the attacks that Bush was resisting their efforts to get documents and question witnesses.

"Why is this administration stonewalling and resisting the investigation into what happened and why we had the greatest security failure in the history of our country?" Kerry said at a hastily arranged news conference.

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"The American people deserve an answer now," Kerry said. "The immediate instinct of the Republicans and this administration was to shut it down."

"This is another inaccurate attack by John Kerry," responded Bush campaign spokesman Scott Stanzel (search). "President Bush and his administration have provided extraordinary cooperation and unprecedented access" to the commission. He said it has provided more than 2 million pages of documents and other materials such as computer disks and tape recordings, in addition to providing extensive briefings and submitting to more than 560 interviews.

"As the chairman of the commission said, not a single person has refused to be interviewed," said Stanzel. He accused Kerry of "trying to distract voters from realizing that his plans would make us uncertain in the face of danger."

Bush has made clear that he will use his leadership after the Sept. 11 attacks in arguing his case for a second term. He began running campaign commercials last week that include images of the destruction at the World Trade Center.

Kerry, who is moving to challenge Bush on that front, said the public deserves an answer as soon as possible about what went wrong leading up to the attacks, which killed nearly 3,000 people in New York, Washington and Pennsylvania.

"Nothing could be more important to the American people at this moment," he said. "They need to know why we had such a failure of intelligence."

He also argued that Bush has pushed a report on potential intelligence failures back until 2005, "which just happens coincidentally to not be an election year."

Last month, Bush named a commission to "figure out why" inspectors haven't found the weapons that intelligence experts said Saddam was hiding in Iraq. He told the panel to report back by the end of March 2005.

By blocking access to information needed for one investigation and delaying the results of another, Kerry said Bush was trying to cover for political purposes any potential failures by his administration.

"They want to get it out of the way as fast as they can so the memory of Americans might be shorter," said Kerry.

At the news conference, Kerry also said he had spoken and planned to meet with vanquished presidential rivals John Edwards and Howard Dean. Aides said they anticipated arranging a session with Dean this week, likely in Washington.

"I look forward to meeting with him," Kerry said. "We're going to discuss winning the presidency of the United States."

The meeting is potentially important because the former Vermont governor built a large fund-raising network on the Internet, and his list of potential donors could be very valuable as Kerry seeks to match Bush's fund-raising prowess.

In addition, Kerry said he will ask advisers and allies to travel to Iraq to prepare an independent assessment of the situation there. Kerry said he hadn't ruled out going himself, but "that's not on the front burner."

"I don't want any sense of politicization in that regard," said Kerry.

Kerry spoke during a four-day campaign swing through the South, and compared his campaign struggles to those of the civil rights movement on an important anniversary.

At a predominantly black church, he told supporters to brace for a wave of criticism from Bush's well-funded re-election campaign, much as civil rights marchers fought against entrenched opposition.

Kerry spoke on the 39th anniversary of the "Bloody Sunday" clash in Selma, Ala., when state troopers used tear gas and billy clubs against activists marching over the Edmund Pettus Bridge. Scenes from that episode galvanized the civil rights movement and within five months the Voting Rights Act of 1965 was passed.