I have an oped on CNN.com explaining why SCOTUS should adopt a Code of Judicial Conduct. Here is the gist:
While Supreme Court justices obviously face the same quandaries and dilemmas as all other judges, they alone have no set rules for resolving, or even addressing, ethics issues.
Members of Congress have repeatedly called on the justices to adopt an ethics code. Most recently, Sen. Chris Murphy, D-Connecticut, and Rep. Louise Slaughter, D-New York, introduced the Supreme Court Ethics Act of 2017, which would give the court six months to "promulgate a code of ethics" based on the Code of Conduct for US Judges already in effect for the lower federal courts, along with any modifications that "the Supreme Court deems appropriate."
[T]he objective of a code would be to set discernible standards for the justices' conduct so that the public could know the norms to which the justices are holding themselves.