Fish's citation to Augustine is interesting but ignores the important distinction in the Blagojevich case. A commenter reminds what others seem to forget:
The problem with this argument is that Blagojevich’s Senate appointment is not tainted for some crime Blagovevich committed years ago. Nor is it tainted because he is an embezzler or a drunkard or a liar. It is tainted because he was caught trying to sell the Senate seat.
Of course Augustine's writings on the Donatists became more problematic when he he endorsed the use of state violence against the Donatists and all "heretics." There is, not surprisingly, much earthly concern in Augustine's reasoning here. Less heavenly concerns. But I always found Augustine to have a lot more concern for earthly things than appeared seemly for a religion that proclaimed itself to be rendering on to God what is God's and to Caesar what is Casesar's.
On the non-"moral" front, Fish also fails to consider the legal powers of the Senate pursuant to Article 1, Section 5. Fish writes:
The legitimacy of an appointment can be either a procedural or a moral matter. If it is a procedural matter, authority is conferred by the right credentials, and that’s that. If it is a moral matter – only the good can be truly authoritative (this was John Milton’s position) – authority is always precarious, and the structures of government and law are always in danger of being dissolved.
The (perhaps paradoxical) truth is that while governing has or should have a moral purpose — to safeguard and advance the health and prosperity of the polity — it is not a moral practice. That is, one engages in it not by applying moral principles but by applying legal principles. Senator Reid and his colleagues in the Democratic party seem finally to have figured that out, which is why, in the absence of any more bombshell revelations, Roland Burris will be seated as the junior senator from Illinois.
Pretty words indeed. But the legal principles contained in Article 1, Section 5 of the Constitution are precisely what is in dispute. There is a credible (indeed, I believe correct) legal argument that the Senate can refuse to seat Burris because of the "sins" of Rod Blagojevich. It appears to require applying a "moral" principle - to me an uncontroversial one - Governors who try to sell a Senate seat should not be allowed to exercise the power of appointment to that seat. The legality of application of this moral principle derives from Article 1, Section 5 which grants the Senate the power (indeed the responsibility) to be "the Judge of the Elections [and] Returns of its own Members."
Can the Senate exercise this power by refusing to seat an appointment by a Governor who is credibly accused of trying to sell the seat? My view is that if the Senate can not, then under what circumstances can the Senate refuse to seat? Why have Article 1, Section 5 at all?
Of course there is another question - which is SHOULD the Senate exercise this power IN THIS CASE. I think they should. I have not really seen an argument addressing why they should not. I do not believe Fish made one that addresses the facts of this case.
Speaking for me only
