Vice President Dick Cheney led the charge, saying Thursday that suggestions by some Democrats that the attacks could have been prevented were "thoroughly irresponsible and totally unworthy of national leaders in a time of war."
Speaking Thursday night at the New York state Conservative Party's annual dinner, he warned Democrats "to not seek political advantage by making incendiary suggestions ... that the White House had advance information that would have prevented the tragic attacks of 9-11."
The White House has acknowledged that a month before the Sept. 11 attacks, President Bush was told by U.S. intelligence that Osama bin Laden's al Qaeda terrorist network might hijack American airplanes. That prompted the administration to issue a private warning to federal agencies.
But the White House insists the information was too general to take more specific action
"I don't think anybody could have predicted that these people would take an airplane and slam it into the World Trade Center, take another one and slam it into the Pentagon," Bush's national security adviser, Condoleezza Rice, said.
The public was not informed of the threats, which administration officials called vague and uncorroborated. Congressional Democrats, and some Republicans, have demanded to be told what the president knew about terrorist threats before the attacks.
Lawmakers say pressure is building for an independent commission to investigate what the government knew in advance of the attacks and whether there was a failure among various federal agencies to respond adequately.
"Was there a failure of intelligence? Did the right officials not act on the intelligence in the proper way? These are the things we need to find out," said House Democratic leader Richard Gephardt.
At the behest of the president, Cheney said he is working with House and Senate leadership to investigate any intelligence failures. He also said the White House would cooperate fully with the probe, but he urged that it be handled professionally.
"The investigation undertaken must protect sensitive sources and information, must be devoid of leaks and it must avoid sensational and outrageous commentary," he said.