Exactly What are the Qualifications of a Justice?

All I have heard on the news today is commentary on President Obama’s nomination of Sonia Sotomayor to the Supreme Court. While some sources offer evidence based criticism or support of her nomination that relates to the role she will have as a judge, the majority of the coverage I have seen have focused on her ethnicity, her socioeconomic background, or her general political views.

What I do not understand is what these things have to do with how Judge Sotomayor will perform as a justice of the Supreme Court. I have heard arguments that her unique background will give her empathy to underrepresented groups and that the fact that she is a Latina marks a step forward for minorities, but these arguments fail to deal with the real question: Will she do her job well? In order to address this question, as well as demonstrate the irrelevance of the aforementioned arguments, we must remind ourselves of the role of a Supreme Court Justice.

The principle responsibility of Supreme Court Justices is to rule on the constitutionality of currently enforced law. It is not their role to recommend, mandate, endorse, or otherwise influence policy, at least not through their formal position (it is another matter entirely for them to act on their political views when they are not on the bench). As a contrast, it is the role of elected politicians to influence the development and implementation of policy. The last thing I want is a justice who seeks to influence policy through the judicial structure. The result would be a breach of the separation of powers which is one of our most valuable lines of protection from the whims of individual politicians who are thinking more about their career than what is best for the country.