One of the current problems in our society is that qualifications for almost every job seem to be based on “what” a person is rather than “who” that person is. Most of us wouldn't care if our plumber were Caucasian or Latino, male or female, Baptist or Presbyterian, as long as the massive leak in our kitchen was promptly and correctly repaired. The reality though, is that plumbers do not render decisions that have moral implications or affect the lives of people in every corner of the nation, and so for that reason, it is important to examine how a particular nominee's faith and commitment to that faith might impact the decisions rendered, but no nominee should be rejected based on religious affiliation.
One of the reasons that religious affiliation should not affect the consideration of a nominee is that it does not seem to be a very good indicator of how a judge will rule. For instance, the most controversial decision of the court, Roe v. Wade, determined that a woman's right to abortion should be upheld. That 1969 court was exclusively mainline protestant. So, one has to ask, would that controversial decision, strongly condemned by the Catholic church, be re-visited and overturned by the proposed two-thirds Catholic, one-third Jewish court? No. We all know that this just won't happen!
It is also important to keep in mind that within any particular religion or denomination, there are vast differences of opinion on social matters, as well as varying degrees of personal dedication and adherence to faith.
Some have also expressed concern that the make-up of the court would not be reflective of the religious affiliation of the nation as a whole. However, it should be pointed out to those who raise this issue that the court as it currently stands is already not representative of our nation. If Kagan is confirmed, all of the justices will hail from elite northeastern schools. Where one is educated often influences world views, so this might be a better indicator of the lack of diversity on the current court. Does an entire court from one corner of the United States fairly represent the entire nation?
In the end, what we need to keep in mind is that a Supreme Court justice's role is to interpret the constitution. The constitution itself has a level of self-protective morality built into the text and meaning. Every justice's religious views will come into play just as their educational background and upbringing will undoubtedly affect how they think and rule. The real issue here is not a particular nominee's affiliation with a particular religion or denomination, but rather an inquiry into what their future rulings may be like. Much can be ascertained by looking at past decisions, past publications, and personal conduct. The Senate is charged with making these inquiries through research and proper questioning during the confirmation process. As in all areas, including selecting Supreme Court nominees, we need to go back to examining “who” someone is--how they think, how they act, how they treat others, who they are as a person, rather than embracing or discarding them based on “what” they are.