WOW. This is quite a dramatic moment. Its hard to imagine Ashcroft, who really was no friend to civil liberties, taking such a stand. It says a lot about this program.

If I'm reading the transcript correctly, it seems that most of the highest-level officials in DOJ were ready to resign over the NSA Surveillance program when the White House decided to continue it without DOJ approval. The Office of Legal Counsel under Jack Goldsmith had come up with parameters under which DOJ was willing to approve the program as legal — perhaps within the scope of the AUMF? who knows — and it sounds like the then-existing program was broader than what OLC thought was permitted. Comey agreed with OLC's legal analysis, so he wasn't willing to give DOJ's approval to the program. So Card and Gonzales (then WH Counsel) go to Ashcroft at the hospital to try to persuade Ashcroft to overrule Comey. Comey gets word of what is happening, and he gets to the hospital first and tries to get Ashcroft ready for Card and Gonzales. Comey explains:

And so I raced to the hospital room, entered. And Mrs. Ashcroft was standing by the hospital bed, Mr. Ashcroft was lying down in the bed, the room was darkened. And I immediately began speaking to him, trying to orient him as to time and place, and try 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 . . . I tried to see if I could help him get oriented. As I said, it wasn’t clear that I had succeeded.  Soon Goldmsith and the ADAG are there by Ashcroft's bedside, and a few minutes later Gonzales and Card arrive... They greeted the attorney general very briefly. And then Mr. Gonzales began to discuss why they were there — to seek his approval . . . .

And 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, which stunned me — drawn from the hour-long meeting we’d had a week earlier — and in very strong terms expressed himself, 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, and I was just to his left.

Feingold says: "Some of the most dramatic testimony that I've heard in 25 years that I've been a legislator."

The Volokh Conspiracy - Full Transcript of Comey Testimony on NSA Surveillance Program: