The events of September 11, 2001, gave Bush the excuse to procure absurd legal advice that, as commander-in-chief in a war on a high-order abstraction, terrorism, he has the power to do what he liked with the lives of millions at home and abroad. He soon signed a secret executive order instructing the National Security Agency's 30,000 operatives to spy without a warrant on US citizens. Whatever certain lawyers or judges might say, this was plainly unlawful under the Fourth Amendment (1791) to the US constitution. It states: "The right of the people to be secure in their persons, houses, papers and effects against unreasonable searches and seizures shall not be violated, and no warrants shall issue but upon probable cause supported by oath or affirmation and particularly describing the place to be searched, and the persons or things to be seized."

The unlawful violations of people's security remained hidden for more than four years until The New York Times revealed them in December 2005. Bush periodically renewed the order and the former attorney-general John Ashcroft had to certify it was legal, but James Comey supervised a re-evaluation soon after he became deputy attorney-general in December 2003. A week before the next renewal, due on March 11, 2004, Comey, Ashcroft and the FBI director, Robert Mueller, agreed that the spying was illegal, but Ashcroft was shortly in intensive care with gall-bladder pancreatitis. His wife, Janet, banned all visitors and telephone calls.

Comey, now the acting attorney-general, told the White House on March 9 that he would not certify that the spying was legal. The reaction of Bush and his people, as revealed by Comey's jaw-dropping evidence to the Senate Judiciary Committee on May 15 this year, put commentators in mind of the scene in The Godfather in which Al Pacino saves the hospitalised Marlon Brando from being whacked by his enemies.

Not long before 8pm on March 10, 2004, Bush telephoned Janet Ashcroft at the hospital to say his legal adviser, Alberto ("Seedy") Gonzales, and Bush's chief-of-staff, Andrew Card, were on their way to see Ashcroft. Janet Ashcroft got a warning to Comey, who was being driven home by his FBI security detail. He understood that Bush was making "an end run" round him to get Ashcroft to sign. Speeding to the hospital with the siren on and the lights flashing, Comey told two of his lawyers to go there. Mueller said he would join the resistance. At the hospital, the towering two-metre tall Comey "literally ran up the stairs". Ashcroft's room was dark; Comey tried to see if he "could focus on what was happening and it wasn't clear to me that he could. He seemed pretty bad off."

Contacted by Comey, Mueller "instructed the FBI agents present not to allow me to be removed from the room under any circumstances". Comey sat in an armchair to the left of Ashcroft's bed. His officers, Jack Goldsmith and Patrick Philbin, stood behind him. Janet Ashcroft held her husband's arm. "And," Comey said, "we waited."

Minutes later, Gonzales, carrying an envelope, and Card arrived. Ignoring the phalanx, Seedy told Ashcroft he was there "to seek his approval" for the renewal. Comey said: "Attorney-General Ashcroft then stunned me. He lifted his head off the pillow and in very strong terms expressed his view of the matter, rich in both substance and fact … and then laid his head back down on the pillow, seemed spent, and said to them, 'But that doesn't matter, because I'm not the attorney-general … There is the attorney-general', and he pointed to me." Gonzales and Card turned and left, but Card soon after called Comey and "demanded that I come to the White House immediately". Comey said he "would not meet with him without a witness present".

Bush alone renewed the order on March 11, but the following day Comey and then Mueller told him that they and other Justice Department officers, probably including Ashcroft, were ready to resign on the issue. Bush understood what that portended. In October 1973, he was 27 and a drunk but he was involved in Republican politics and he knew that impeachment bills followed president Richard Nixon's Saturday night massacre of Justice Department lawyers. Bush told Mueller to tell Comey to put the spying on a proper legal footing.

It is a pity that Bush did not mulishly persist. The resignations would have revealed the illegal surveillance and it is probable that even John Kerry would have become president eight months later and that the war in Iraq would be over. Evan Whitton is a columnist for the legal journal, Justinian, in which a version of this article first appeared. He is the author of Serial Liars: How Lawyers Get the Money.