Both sides of the mouth
On the other hand, these same liberal groups decry conservative criticism of court decisions. (See, e.g., PFAW's April 2005 "Right Wing Watch".) Can you imagine the liberal uproar about "judicial independence" if a conservative group were to oppose the appointment to a federal district court judgeship (say, by a President Hillary Clinton) of Judge George Greer (the Florida state judge who oversaw Terri Schiavo's starvation/dehydration) because of his "troubling" management of that case?
Maybe the rule is that it's okay to block appointments and promotions in retaliation for decisions, but not okay to criticize judges who are not up for higher appointment.
Or maybe the rule is that it's okay to lambast judges for conservative decisions, but not for liberal ones . . . .