Ashcroft flatly refused to give the Senate Judiciary committee the torture memos (3 that are known to exist, are there more?), refused to invoke Executive Privilege (which he can't do anyway, the pRes has to), and couldn't declare any statute or other reason to refuse the release. As was pointed out to him by Joe Biden, Dick Durbin, and Pat Leahy, that leaves him in contempt of Congress.
I haven't been able to find anything in the Rules of the Senate or the rules of the Judiciary committee on a contempt proceeding -- who can initiate it, what happens, what the penalties are.
If it requires a majority vote of the committee, I don't think Hatch can block it, with the 9 Dems and Lindsey Graham (maybe even Grassley, he's really bent about the Edmonds thing). But then what would happen if the committee does vote it out? Does the full Senate have to vote on it? What are the penalties? Is the case then referred to the District Court, or ???
The other question is, will Dubya leave Ashcroft to carry the can or invoke Exec Priv? This misAdmin has gone to great lengths to avoid taking that step so far, and 5 months before an election isn't a good time to start.