Determined to prove his fitness, Mukasey checked out of George Washington University Hospital shortly after noon, telling reporters he felt "excellent." Arriving at the Justice Department a few minutes later with his wife, Susan, Mukasey climbed out of his security van unassisted and showing no signs of pain or discomfort.
In an e-mail to the department's 108,000 employees, Mukasey said he would "continue doing the work I swore to do last November" when he became President George W. Bush's third attorney general.
"As you may have heard, I collapsed briefly last night at the conclusion of a speech," Mukasey wrote. "All tests at the hospital have come back with good results, and I feel fine."
Leaving little doubt about his plans to stay on the job for the last two months of his tenure, Mukasey added: "It has been and remains an honor to serve with you."
Mukasey was the keynote speaker at a black-tie dinner Thursday night for The Federalist Society, a conservative legal group. He opened his speech about the Bush administration's fight against terrorism with a wry remark about expecting the mood at the dinner to be "somber or sober."
Around 10:10 p.m. EST, Mukasey was about 20 minutes into his speech when he began shaking and slurring his words. He repeated a phrase - "as a result" - three times and then slumped forward on the podium. His FBI security detail ran to catch him as he fell.
"Oh, no, no!" people in the audience cried out as Mukasey fell. "Oh, my God!"
Flitting in and out of consciousness, Mukasey lay on the stage for about 10 minutes as FBI agents and medical personnel at the dinner sought to help him. He was then rushed to the hospital, where he remained overnight for tests and observation.
Mukasey is not the first attorney general to faint publicly. Clinton administration Attorney General Janet Reno fainted twice - during a 1998 church service in suburban Maryland and while attending a 1997 conference in Mexico City - in episodes blamed on exhaustion.
Other publicly viewed health scares by top U.S. officials include when Clinton administration Commerce Secretary William Daly fell off a stage and when then-President George H.W. Bush became sick at a Tokyo dinner.
President Bush telephoned the attorney general shortly before 7 a.m. EST to wish him a speedy recovery, press secretary Dana Perino said, describing Mukasey as "sounding well" and saying he was getting "excellent care."
The Justice Department said President-elect Barack Obama also was among the well-wishers to call Mukasey during the day, which the attorney general spent in briefings and having lunch with his wife. He planned to spend the weekend at his home in New York and be back in Washington for business as usual Monday.
Justice Department spokeswoman Gina Talamona said Mukasey had passed a treadmill stress test, a stress echocardiogram, CT scan and an MRI. She also said doctors ruled out a cardiac problem or stroke, and specifically ruled out TIA - or transient ischemic attack - which is a mini-stroke.
"It really appears to be a fainting spell," Talamona said.
Mukasey "works long days," she said. "He's very active. It was a late-night speech under hot lights." She said he has no pre-existing health problems, and that he works out daily on an elliptical machine.
Mukasey, a flinty but measured former federal judge, has scaled back his public appearances in recent weeks. He was described as tired-looking and drawn by a former federal prosecutor hours before he collapsed. In an interview last year early in his tenure, he called the attorney general's job discouraging.
The native New Yorker stepped in as the nation's chief law enforcement officer after the resignation of former Attorney General Alberto Gonzales, who left under fire in a controversy over the firings of several federal prosecutors.
Abigail Thernstrom, a senior fellow at the Manhattan Institute, attended Thursday's dinner at the Marriott Wardman Park Hotel in northwest Washington. She described Mukasey's fall as "horrible."
"It was hard to watch such a thing," she said.
