Check out Brian Tamanaha’s Distinguishing Law From Ideology in Judicial Decisions on Balkinization. Here’s a taste:
Imagine two judges, both with politically conservative personal views: One decides cases with a conscious orientation that strives to abide by the binding dictates of applicable legal rules to come up with the most correct legal interpretation in each case (the Consciously Bound judge, CB); a second judge decides cases with a conscious orientation that strives to achieve ideologically preferred ends in each case, and interprets and manipulates the legal rules to the extent necessary to achieve the ends desired (the Consciously End-Oriented judge, CEO).
Add four realistic conditions to this scenario. First, notwithstanding having a legally bound conscious orientation, CB is subconsciously influenced by and sees the law through background personal views; the legal interpretations of CB are thus not completely free of political influences in this subconscious sense. Second, CEO is not able to achieve ends with total disregard for conventional legal understandings because the decisions must be legally plausible and have the external appearance of being rule bound. Third, in a large (but not total) subset of cases the law does not clearly point to a single outcome, though usually one outcome can be ranked as more legally compelling or defensible than others. Finally, in a subset of cases, the legal rules are open (no particular outcome can be ranked above any other) or they invite the judge to render a judgment based upon non-legal factors.
Now, imagine that, in a given case, both judges arrive at precisely the same (politically conservative) outcome, supported by identical written decisions; they would have joined opinions had they served on the same panel. They are led to the same result and use the same reasoning because they adopt the same theory of constitutional interpretation. The difference is that CB settles upon the theory as the correct way to interpret the Constitution following a sincere and exhaustive study of constitutional law, whereas CEO settles upon the theory because it tends to support the outcomes the judge personally prefers, and CEO is willing to depart from or “adjust” the theory when necessary to achieve a desired end in particular cases.
Interestingly, a behaviorist study would code these two cases in exactly the same way: as a legal decision that aligns with (and hence can be explained by) their conservative political ideologies. Indeed, by all external appearances the decisions are exactly the same. Yet this misses fundamental differences in their reasoning processes and in the contrasting way they would be normatively judged by others. CB is acting in a rule bound fashion, consistent with the duty of judges within our system, while CEO is abusing his power as a judge by engaging in a manipulative (insincere) interpretation of the law to advance a desired political end.
And while you are at, also take a look at Brian’s Judge Posner’s Seductive Realism and Pragmatic Adjudication–Beware the Pied Piper. Truly excellent blogging!