While I believe the current situation of the US Supreme court frightens conservatives, I think it should not. If Obama selects a leftist Judge, and there is no reason to think he won't, the 8 year run of Obama has been sealed. They will have proof that the acts, government changes, and social upheavals orchestrated by Obama and his allies will be the law of the land. By stomping their feet and acting angry the GOP does not demonstrate leadership in the opposition, they demonstrate petulance and fear.
If the situation facing the US voter in November 2016 is Bernie Sanders, Socialist, or Hillary Clinton, Center Left versus someone on the Right, the GOP should feel confidant that if they are relevant the American voters will rise up and choose a Republican, to turn back or slow the change. The attempts to change the rules and force Obama into an recess nomination or some sort of back door selection does not prove Obama is weak, but that the GOP is afraid that their brand is no longer viable.
Just remember what Gowron said: "Destroying an Empire to win a war is no victory. And ending a battle to save an Empire is no defeat."
Choose your battles, do not fight when you should be gathering forces.