Here is an interesting little thought to consider as the Republicans consider obstructing an Obama appointment to the Supreme Court:
Consider the 20th Amendment to the United States Constitution:
Section 1. The terms of the President and Vice President shall end at noon on the 20th day of January, and the terms of Senators and Representatives at noon on the 3d day of January, of the years in which such terms would have ended if this article had not been ratified; and the terms of their successors shall then begin.
Consider this basic scenario. Obama appoints a highly qualified justice to the Supreme Court, and the Senate refuses to act. There are several GOP senators in this cycle who were elected from blue states in 2010, and obstruction against a court appointment is likely to be an issue in those races. Democrats take control of the Senate on January 3, 2017, and (by majority vote) enact a set of rules allowing for swift confirmation of a Supreme Court justice. A new justice could be seated before January 20, 2017.