Just some thoughts on Roberts vis-a-vis Katrina: the Democrats at the hearing, or speaking outside of it, could be well advised to show public distaste that the hearings were not delayed because of Katrina, and condemning the Administration for not doing so. (Not in a raging way, but with due subtlety)
Also, Katrina could offer a topic off of which to ask Roberts about the role of government. E.g., "Mr. Roberts, you had no problem with government being used to arrest a 12-year-old girl eating a French fry in a subway station. However, you seem to DECRY the use of government to help people, as in affirmative action, sex equality, etc. Would you care to explain this massive discrepancy, where you are comfortable with intrusive, violent government action that does no good, whereas the next moment you are uncomfortable with benevolent government action, of the kind which the people of New Orleans and the Gulf Coast have cried out for for days?"