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.
Exit polls also muddy the picture. Obama made inroads on Clinton's strength by winning 37 percent of Pennsylvania voters over age 65 compared with his 26 percent in Ohio. And he took 44 percent of white men, up 5 points from Ohio. But in one big swing group, he was found wanting: Only 60 percent of Democratic Catholic voters said they would vote for him in a general election, while 21 percent said they would vote for John McCain.
In the end, such reading of primary tea-leaves may not sway the 300. Their choice could be more fundamental.
They need to decide if the party wants to adopt Obama's line that "going negative" in campaigns would only further feed the kind of political polarization and legislative inaction in Washington that voters resent. Or do they see in Clinton's "tough tactics" against her opponent the kind of ruthless leadership that would help Democrats steamroll the GOP in both the election and in Congress?
Many of Obama's "negatives," of course, are self-inflicted, such as his comments on "bitter" rural folk. And his past associations may yet erode his message of hope and change. But he's been relatively restrained in "going negative" compared with Clinton's recent barrage. "If you can't stand the heat, get out of the kitchen," the narrator of the recent Clinton TV ad says.
Their campaign styles are telling of what kind of president each might be. For superdelegates caught on the fence of interpreting primary results, they must ask if the party wants a nominee whose tactics will carry over to the general election against Mr. McCain, then the White House, and ultimately to creating a different America.
Clinton won this primary squarely, but 68 percent of voters thought that she had "attacked unfairly." With mixed messages like that, the 300 will need Solomonic wisdom.