Clinton's victory only enhances their role in deciding whose campaign style is the better.
Imagine being one of the 300 or so undeclared Democratic superdelegates digesting the Clinton win in Pennsylvania. Forget that the high voter turnout reflects a wish not to let these party insiders pick the nominee – they probably will. Her win makes this privileged decision of the 300 more difficult.
The primary's numerical results only supersize the agony for the unelected Deciders whose levers aren't in voting booths. Their coming choice risks offending entire groups of the party's big, but increasingly torn, tent.
Take Mrs. Clinton's nearly 10-point victory over Barack Obama. It's far less than her 20-point lead in early opinion polls. And her victory doesn't give her much in delegates to catch Mr. Obama's lead. For superdelegates, she has come-back momentum but not the narrative of a knock-out blow.
And in the national popular vote from primaries held so far (not counting Florida and Michigan), the Pennsylvania primary cut Obama's lead of about 700,000 by some 220,000. But a superdelegate would only note that he could easily gain much of that back in coming primaries. And some portion of those Clinton votes came from Republicans tactically crossing party lines to boost her.
The Supers may see that Obama's pitch to be a uniter not a divider didn't unite Pennsylvania's Democrats behind him. They now have to wonder about his electability just as much as they have seen Clinton's once-inevitable electability fade away in earlier primaries.