Why, you wonder? Why can't they think for one minute that Sotomayor might be the best candidate for the job?
Well, duh. That's easy. Girls and brown people are never the best people for the job. If they were, God would have made them white and male.
(See an analysis of the validity of the Right's talking points here.)
(See also: ABW on the issue. Don't miss Paul in comments! What a treat! The Angry White Male of Privilege Explains the World to Us!)
(And for further rebuttal see this too.)