He, quite rightly, will not answer questions about "his opinion" on Supreme Court decisions because they are absolutely irrelevent. His opinion is available in his body of work.
Which, oddly enough, the White House won't make available for review. See here [link|http://www.nytimes.com/2003/02/13/opinion/13THU2.html?ex=1045803600&en=7a516d31264e3afe&ei=5062&partner=GOOGLE|New York Times].
All the Congressmen had to go on for Estrada was that Bush backed him and he had a high ABA rating. Needless to say, the first point holds less then 0 weight, while the second was worth something. Until it turned up that the rating was bogus.
He might still be qualified or he might not. But at this point it would be hard for Republicans to give a good reason for voting for him, and everybody else has every reason to reject him out of hand.
Jay