The Senate has no legal basis for rejecting Illinois appointment.
By Barbara Lee
The Congressional Black Caucus unanimously believes that Roland Burris, who was appointed by Illinois Gov. Rod Blagojevich, should be accepted by the Senate to fill the seat that had been held by President-elect Barack Obama. As members of Congress, our unique experience has always compelled us to look to the U.S. Constitution and the rule of law — the only principled guidance available — when determining issues such as whether to seat Burris ...
After Rep. Adam Clayton Powell Jr. was excluded from the House, the Supreme Court, in a 7-to-1 decision in 1969, strictly interpreted Article 1 in Powell v. McCormack. While the Powell case concerned an election rather than an appointment, the Court left no room for Congress to go beyond the qualifications specified in Article 1.
Further, the 17th Amendment allows "the legislature of any state (to) empower the executive … to make temporary appointments until the people fill the vacancies by election as the legislature may direct." The Illinois Code, in turn, provides that "the Governor shall make temporary appointment(s) to fill such vacancy until the next election" ...
No qualified person, appointed or elected according to applicable law and procedures, has ever been excluded from the Senate. (Though the Senate in 1893 and 1913 refused to seat two appointed senators, neither was properly appointed.) We believe that the Senate can seat Burris while upholding the Constitution and preserving the Senate's institutional integrity.
http://blogs.usatoday.com/oped/2009/01/opposing-view-s.html