Here is why . . .
It is always permissible for a judge to discuss the principles of Law, because "Ignorance of the Law is no excuse;" and it is always in the Public Interest for people to know and understand the Law. Therefore judges should always be allowed and encouraged to discuss the principles of Law, as they understand them. Canon 4-A of the "Code of Conduct for United States Judges" clearly says," A judge may speak, write, lecture, teach, and participate in other activities concerning the law, the legal system, and the administration of justice." And Canon 4-B says, "A judge may appear at a public hearing before, or otherwise consult with, an executive or legislative body or official on matters concerning the law, the legal system, and the administration of justice to the extent that it would generally be perceived that a judge's judicial experience provides special expertise in the area." Source: Code Of Conduct For United States Judges - http://www.uscourts.gov/guide/vol2/ch1.html
But it is another thing altogether for a judge to discuss how the law applies to a specific case before his court, or which might come before his court, because the judge must maintain his fairness and impartiality toward all parties in the case. Therefore he must not even appear to have already made up his mind, until the case before him is decided. Canon 3 of the "Code of Conduct for United States Judges" is: "A judge should perform the duties of the office impartially and diligently." Source: Code Of Conduct For United States Judges - http://www.uscourts.gov/guide/vol2/ch1.html
There is one sentence in the "Code Of Conduct For United States Judges" which might seem to require that a judge not comment at all on any pending case, and that is this: "A judge should avoid public comment on the merits of a pending or impending action, requiring similar restraint by court personnel subject to the judge's direction and control." But there is a specific exception which applies to these confirmation hearings: "This proscription does not extend to public statements made in the course of the judge's official duties, to the explanation of court procedures, or to a scholarly presentation made for purposes of legal education." A Senate confirmation hearing would certainly be "a public statement made in the course of the judge's official duties." (Canon 3-A-6) A similar restriction, with a similar exception, is found in the American Bar Association's "Model Code Of Judicial Conduct." (Canon 3-9)
For more information on these subjects, please see the "Code Of Conduct For United States Judges," located at http://www.uscourts.gov/guide/vol2/ch1.html and the "American Bar Association Model Code of Judicial Conduct," located at
So where did we ever get the idea that a Supreme Court nominee should not comment on matters which might come before him in the future?
The usual explanations for this idea go something like these two:
1. "First, what judges do limits what judicial nominees may discuss. Judges must be impartial and independent. Their very oath of office requires impartiality and the canons of judicial ethics prohibit judges and judicial nominees from making commitments regarding issues that may come before them."Source: Sen. Hatch, in his opening statement at the Roberts hearings, as transcribed at www.asksam.com
2. The American Bar Association Model Code of Judicial Conduct dictates, and I quote, "that a judge or candidate for election or appointment to judicial office shall not with respect to cases, controversies or issues that are likely to come before the court make pledges, promises or commitments that are inconsistent with the impartial performance of the adjudicative duties of the office." Source: Sen. Kyl in his opening remarks at the Roberts hearings, as transcribed at asksam.com
Please note that these explanations say that commitments are prohibited and impartiality is required. That seems reasonable to me, and it seems to be consistent with both the "Code Of Conduct For United States Judges," and the "American Bar Association Model Code of Judicial Conduct," (links shown above).
But these ideas do not apply to Judge Alito's confirmation hearing in the Senate, because the Senate not asking Judge Alito for commitments of any sort, just explanations of how he now thinks the Law applies to the various issues he will be facing.
Thus we see that there is no good reason why Judge Alito cannot answer questions about his legal reasoning on abortion, presidential power, torture, wiretaps, religion in public places, the limits of privacy, the limits of free speech (if any) , or any other legal issues which might come before the Supreme Court.
Blessings to you. May God help us all.