The reason Mukasey could not answer the waterboarding question:

Bush said Mukasey could not give such a legal opinion because the program is classified and the nominee has not been briefed on it. Mukasey also did not want to telegraph information about interrogation methods to dangerous detainees, Bush said.
The president also said Mukasey did not want to issue an “uninformed legal opinion” because interrogators in the field would wonder whether any of their conduct places them in legal jeopardy.
“Congressional leaders should not make Judge Mukasey’s confirmation dependent on his willingness to make a public judgment about a classified program he has not been briefed on,” Bush said.
Nominated in September, Mukasey was initially considered a sure bet for confirmation until he repeatedly refused to say in Senate hearings whether he defines waterboarding as torture.
Democrats denounced the dodge, and the chairman of the committee, Sen. Patrick Leahy, D-Vt., announced Friday he would vote against Mukasey.

The Democrats know this, it’s clear they just want to embarrass the president and score political points. If this was such and issue, why are over 20 Democrats expected to vote for him?
BTW, before any of you lefties make any obnoxious comments, I’m totally against torture of any kind. I think there are more effective ways of obtaining information.