As an attorney, Mitchell did something she knows you never do.

[trof]

She asked a witness questions that she didn't already know the answers to.
With no independent investigation and facts to go on she was a fish out of water.
I don't know what the repugs were hoping for, but she wasn't it.

[louis-t]

1. That's why we're back to the angry white men show.

[NanceGreggs]

2. She was limited to asking ...

... the questions set out by the senators she was acting as a surrogate for. She didn't compose the questions herself.

[trof]

3. Ah. Even worse then.

[Jim Lane]

4. I wouldn't say that's a "never"

Ideally, an attorney would prepare for an examination like this to a fare-thee-well. Yes, the attorney would like to know the answer in advance, the chief exception being that you can ask the question if any answer will help you. (For example, "Did you know in advance about the nefarious thing your underling did?" The witness either knew (culpable) or didn't know (irresponsible).)

In this case, however, Mitchell didn't have the kind of control that a lawyer in a criminal or civil case would have. She had to prepare on an extremely rushed basis and with inadequate opportunities for investigation.

As to what the Republicans were hoping for, my guess is that they were hoping she'd hit upon something that would justify Grassley's partisan rush to bring the nomination to a vote. From the accounts I've read, they didn't get it.