Amid warnings that another devastating terrorist attack on the United States could be imminent, Democratic presidential candidate John Kerry (search) on Thursday accused President Bush of leaving the nation's chemical plants vulnerable because of his political ties to the industry.

"I wish their policies were in touch with the tough rhetoric that you keep hearing," Kerry told the National Conference of Black Mayors (search). "What are we waiting for? Instead of misleading us about weapons of mass destruction in Iraq, they ought to lead this nation to take every step to prevent one of our own chemical plants from being turned into a weapon of mass destruction against our own people."

Kerry painted a bleak picture of the danger facing Americans and suggested there could be an attack before the November election. He said every report out of Washington shows that it's not a matter of whether there will be another terrorist attack, but when.

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"So if we know it's a matter of when, then when are we going to stop pretending that all has been accomplished in our shared mission to keep America safe?" he asked. "When are we going to start dealing with dangers that we still know exist in this country?"

Kerry said not all attacks can be prevented because terrorists who are willing to risk their lives are impossible to stop. But he said he has a plan for many vulnerabilities that the Bush administration has not addressed — U.S. ports are not secure enough to prevent nuclear material from arriving by ship, the country's borders are wide open, and the FBI does not share vital information with local officials about suspected terrorists.

The mayors applauded loudly when Kerry said the Bush administration is asking them to protect the homeland, then sticking them with the bill.

The Bush campaign said the administration is doing almost everything that Kerry proposes to protect chemical sites.

"John Kerry has played politics with homeland security throughout this campaign, and today he is doing it again," Bush spokesman Steve Schmidt said. "John Kerry voted against the Department of Homeland Security six times and wants to weaken the Patriot Act (search). His speech today is not a credible alternative but a retread of policies that the president has already advocated."

Kerry said Bush has accommodated the chemical industry, which favors voluntary efforts to improve security, because of campaign contributions from executives.

The Kerry campaign cited pledges to Bush during 2000 and 2004 of at least $1.5 million from 15 fund-raisers it said were tied to the chemical industry. The campaign also cited nearly $6.5 million in soft-money contributions — corporate, union or unlimited donations — from the industry to Republicans during the 2000 and 2002 campaigns.

"This administration unfortunately has been unwilling to take these steps because they have sided with the chemical industry that pushes back," Kerry said. "We don't care who they're writing campaign checks to. It's time for them to make America stronger."

Two years ago, the CIA warned of the potential for an Al Qaeda attack on U.S. chemical facilities. According to the General Accounting Office (search), an investigative arm of Congress, about a fifth of the nation's 15,000 chemical facilities are close enough to population centers that a terrorist attack could harm at least 10,000 people.

Kerry said he will require chemical plants at risk of terrorist attack to implement adequate physical security, including fences, guards and surveillance. He said his plan calls for government action to implement the requirements only if plants fail to act, including assessing their vulnerability on an individualized basis.

The plan mirrors legislation Kerry, a Massachusetts senator, sponsored in early 2003 with Sen. Jon Corzine (search), D-N.J., and other Democrats. It stalled in the Senate over opposition from Republicans, who said it sought to inappropriately micromanage the nation's $450 billion chemical industry.

Kerry would require the Department of Homeland Security to review and certify vulnerability studies for chemical plants deemed high-priority targets. There presently are no legal requirements for such plants to assess vulnerabilities or take security actions to guard against a terrorist attack, although the industry's leading trade group, the American Chemistry Council (search), requires its members to do so.

A key Senate committee approved a compromise bill supported by Republicans in October 2003 that would require security assessments to be sent to Homeland Security, but would not require any formal certification or approval.

An industry spokesman, the chemistry council's Marty Durbin, said government should consider auditing a percentage of all companies' vulnerability studies, not each one.

"At least that provides for an incentive," Durbin said.