What does it mean?

With about one-third of the Pennsylvania primary vote counted, Clinton’s margin is eight percentage points. It has fluctuated between six and ten points. If the margins ends up in that range, the result will be insufficient to cause enough panic among super-delegates to lead them to break for Clinton. On the other hand, it will likely raise or reinforce enough doubt about Obama’s strength to prevent these delegates from breaking decisively for Obama at this point.

In short, on to North Carolina and Indiana.

UPDATE: A little more than half of the vote has been counted now, and Hillary leads by ten percentage points. Moreover, it seems that the half that hasn’t been counted is comprised disproportionately of non-urban areas where Clinton is particularly strong. So now it seems quite possible that Hillary will get her double-digit victory after all. Such a victory probably wouldn’t produce panic at the thought of nominating Obama, but it would increase doubt over the wisdom of doing so.

ONE MORE NOTE: Exit polls showed that only slightly more half of those who voted today consider Hillary Clinton trustworthy. Yet Clinton has won a decisive victory. Obama must be fairly unpopular in Pennsylvania.