This is a fairly simple idea, but may prove effective if pressed repeatedly and publicly.
--Miers is * O'Connor's replacement *, and this gives an opening to compare her to Sandra Day repeatedly and say, "Is this the best you could find?"
SDO'C was third in her class at Stanford Law (first was her occasional date Rehnquist), and an Arizona state senator and appeals court judge.
...while on the other hand, Miers is a party hack, Dumbya's consigliere and former staff secretary, and...Texas lottery board honcho. How impressive. Cough.
"Avenues of attack" could include Senators asking her at the hearing, "How would you compare your qualifications to be an Associate Justice with those of Sandra Day O'Connor, whom you're replacing?"
Or other avenues. Hope to hear your suggestions or criticism,