Law professor and blogger Eugene Volokh takes the same view that I do of the right of the Senate not to seat Roland Burris: Under the 1969 Supreme Court case of Powell v. McCormack, the Senate has no right at all to do that. Interestingly, Adam Clayton Powell, the successful plaintiff in the 1969 case, was African-American, as is Burris. I thought the House's refusal to seat Powell back in 1967 was wrong and an exercise in racism. Powell did indeed have ethical problems, but they could have been referred to the ethics committee and he could have been disciplined or expelled. But so great was the demand by Southern Democrats and conservative Republicans for a rejection of Powell, who was flamboyant to the point of recklessness, that the House voted not to seat him.
I had some sympathy for Powell. He had been a legislative workhorse for Lyndon Johnson's Great Society as chairman of the House Education and Labor Committee. And in the years before he became chairman in 1961, even though he was No. 2 in seniority among committee Democrats, the chairman, Graham Barden, refused to call on him to ask questions. After you've been treated like that for 10 or 20 years and then come into a position of power, you might have become flamboyant to the point of recklessness yourself.
Incidentally, Powell won his court case but lost his seat, in the 1970 Democratic primary, to a young Korean War veteran named Charles Rangel. Today, Rangel is chairman of the House Ways and Means Committee and has some ethical problems himself.
Roland Burris is no Adam Clayton Powell. He seems to be a clueless and conceited cipher, at least according to Steve Chapman and David Broder, who have followed his career more closely than I have. Anyone who is truly his friend would have advised Burris to refuse this appointment. He is not going to exercise the office of senator anytime soon. But if the Senate Democrats vote to exclude him, they may make fools of themselves, too. Burris could sue and win a quick decision from a federal court based on the clear precedent of Powell v. McCormack. That case's holding that the House cannot refuse to seat a duly elected representative would seem to dictate a ruling that the Senate cannot refuse to seat a duly appointed senator. And if you want to argue that an appointed senator has somehow less standing than an elected senator, you'd have to deal with the fact that the Constitution originally provided for the election of senators not by voters but by state legislators and for appointments of senators to fill vacancies when legislatures were not in session (which they often weren't).
So far as I know, the Senate has no reason to bar or expel Burris except that he has been appointed by Rod Blagojevich. But that is an objection that would seem far more relevant to the question of whether he should be seated than to the question of whether, once he is seated, he should be expelled. If Powell v. McCormack stands in the way of the Senate refusing to seat Burris, then it would seem a sense of justice stands in the way of saying that he should, once seated, be expelled. But maybe not. Somewhere back in my memory, I recall that a Michigan senator named Truman Newberry was either prevented from taking his seat or expelled from the Senate for the offense of having spent too much money in his 1918 campaign against none other than Henry Ford. I suppose that example is a case in which a senator whose conduct was otherwise unexceptionable could be expelled for the means by which he procured the seat. But we have no evidence that Burris gave Blagojevich anything except his undertaking that, yes, he, unlike most Illinois politicians, would accept the appointment.