The nomic-ness of the first couple sentences of this paragraph struck me: The tricky part here is that Article 1 of the Constitution stipulates that the Senate is the "Judge of Elections, Returns and Qualifications" of its own members. The Senate actually has fairly broad latitude on questions of "Elections and Returns", which is why it could intervene, say, in the Minnesota recount (as it has done in similar cases in the past). An appointment, however, is not an election, which means the only vehicle open to the Senate is challenging the appointee's qualifications, and the Powell v McCormack precedent stipulates that such a review would be limited to his age, residency or citizenship. What the Senate would have to do instead is actually expel the member they just admitted to the chamber, which requires a 2/3 majority and would be much stickier in terms of precedent -- the Senate has not expelled a member since the Civil War.
Full story with other nice constitutional detail analysis: http://www.fivethirtyeight.com/2008/12/senate-might-not-have-authority-to.html
