Frank Apisa wrote:Can anyone tell me:
Is there anything in the Constitution that prohibits the Supremes from looking wherever they want to when making their decisions?
Judges can look practically anywhere for arguments to support their rulings. But there's a difference between
binding authority and
persuasive authority. Courts are bound by their own decisions and the decisions of higher courts (in the case of the SCOTUS, of course, there is no higher court). The SCOTUS can overrule its previous decisions (as in, e.g.
Brown v. Board of Education), but it does so only rarely. In most cases, the SCOTUS treats its previous decisions as
binding, and it is obligated to follow those precedents.
A court can cite foreign court decisions, but it cites them only as
persuasive. That is to say, the SCOTUS can cite a French or German judicial opinion, but only as a way of demonstrating that other courts elsewhere have faced a similar situation and have dealt with it in a manner that ought to be imitated (or avoided). Those foreign decisions, however, have no
precedential effect: the court is not, in other words, obligated to follow those decisions (the only exception is English case law prior to July 4, 1776, which is treated as binding on American courts through the notion of "incorporation" of the English common law).
Frank Apisa wrote:What constraints are placed on them by the constitution?
None. These constraints have been placed on the courts by the courts.