But see: Article I, Section 5, Clause 1:
Each House shall be the Judge of the Elections, Returns and Qualifications of its own Members, ..."
The Supreme Court, in Barry v. United States ex rel. Cunningham, 279 U.S. 597, 615 (1929) held that refusal to permit a person presenting credentials in due form to take the oath of office does not deprive the State which elected such person of its equal suffrage in the Senate.
Dingy Harry Reid is on solid grounds.
Harry imagines he can simply ignore Blago's nominee, but the Constitution does not support him on that.