The chances of the GOP both winning the presidency and holding the Senate in 2016 are somewhat less than 50%. I think pretty much any nominee can defeat The Liar or The Socialist, but I'm not convinced that any nominee will have the coattails to help the GOP retain the Senate in an unfavorable election cycle.
The Senate is sworn is before the President, which means that even if a Republican wins the presidency, a new Dem Senate majority would be able to confirm an Obama appointment before the new president could withdraw it. So all in all, the Dems are sitting in pretty good shape to replace the bulwark of Originalism with another "Living Constitution" liberal. That's unfortunate for the rule of law. In a reasoned and just society, laws must be interpreted first and foremost upon what they say - not based upon the result the justices hope to reach.