It occurs to me that a reasonable alternative hypothesis is that the Attorney General's aides have not briefed him properly. The truth is that every Administration witness gets briefed before testifying before Congress in regular oversight hearings (as opposed to investigative hearings of the sort that are going on now), and much of the information comes from the briefing materials that are put together by underlings. The idea is to make sure that the witness knows the things he should know. In this case, of course, Gonzales didn't. This could come about in three ways:

First, the aides could be incompetent themselves, and not have prepared the briefing books properly before his appearances.

Second, they could be perfectly competent, but have decided that it was better if Gonzales didn't know certain things. This is not an uncommon strategy, and the idea often goes without saying. After all, it's not a lie if you don't know the truth.

Third, Gonzales could have instructed his aides not to prep him on certain things. Again, if you don't know the truth, it's not a lie.

All of this, of course, is consistent with the general Bush Administration approach of keeping as much information as possible under wraps. That makes me lean towards the second and third possibilities, but none of these options requires Gonzales to be incompetent. All he has to be is intentionally oblivious, and he's apparently pretty darned good at that.

That, and he tends to hire 30-year-olds who went to Regent University Law School. So you may be on to something with your first point too. Either way, it's all quite depressing.