The issue is whether McCain would name a conservative that would tip the balance of power. I don’t think he will do it. He didn’t like Alito even though he voted for him.
I don’t think we get a consevrative either way so why should we vote McCain just because he *might* name a conservative but probably won’t? That seems like a really weak reason to support so repulsive a nominee.
We know that Hillary or Obama won’t, of that we can be certain.