I found this interesting quote on US v. Nixon on Wikipedia while looking up case law on the separation of powers:
"The unanimous decision held that the Supreme Court has not only the power established in Marbury vs. Madison to rule a law invalid for conflicting with constitutional provisions, but also power to decide how the Constitution limits the President's powers; that the Constitution provides for laws enforceable on a president; and that executive privilege does not apply to "demonstrably relevant" evidence in criminal cases."
http://en.wikipedia.org/wiki/United_States_v._NixonFor all you lawyers out there, if US v. Nixon found that the Constitution provides for laws enforceable on a president, then doesn't that eliminate the argument for a Unitary Executive since that theory implies the President can act counter to constitutional provisions and established US law (as in warrantless wiretapping, signing statements reserving the right to torture, etc.)?
Some interesting tidbits from US v. Nixon:
"The District Court held that the judiciary, not the President, was the final arbiter of a claim of executive privilege."
and
"Notwithstanding the deference each branch must accord the others, the "judicial Power of the United States" vested in the federal courts by Art. III, 1, of the Constitution can no more be shared with the Executive Branch than the Chief Executive, for example, can share with the Judiciary the veto power, or the Congress share with the Judiciary the power to override a Presidential veto. Any other conclusion would be contrary to the basic concept of separation of powers and the checks and balances that flow from the scheme of a tripartite government. The Federalist, No. 47, p. 313 (S. Mittell ed. <418 U.S. 683, 705> 1938). We therefore reaffirm that it is the province and duty of this Court "to say what the law is" with respect to the claim of privilege presented in this case. Marbury v. Madison, supra, at 177."
http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=CASE&court=US&vol=418&page=683US v. Nixon is interesting reading in context of Bush's warrantless domestic spying and his use of signing statements to ignore laws passed by Congress. His claims of unitary executive powers would appear to be voided by the precedent of US v. Nixon. It certainly explains why Bush wants to get justices on the court who support the Unitary Executive, since they could conceivably ignore the precedent in US v. Nixon and rule in Bush's favor in any subsequent litigation. I have NO faith that Bush appointed justices would recuse themselves.