I believe Obama will appoint Scalia's successor, and that McConnell and the Senate will confirm anyone Obama wants, including the odious Eric Holder.
Imagine a 5-4 Supreme Court decision interpreting the 2nd Amendment to ban the mere possession of handguns. It could happen. MILLIONS of us would not comply, of course. Any attempt to force us would lead to mass death.
But this one event, Scalia's death, could be the inflection point of the downfall of the American Republic, and quite possibly the traceable initiation of the 2nd American Civil War.
Scalia’s death could be the equivalent of the Dred Scott decision of 1857.