In a Senate election, the popular vote has clear meaning. In a presidential election, the popular vote is less meaningful because the electoral college is what matters, but at least there's a relatively uniform set of rules from state to state. (If Bush had clearly won Florida, there would have been heartache, but not nearly as much controversy.)
But in the Democratic presidential nomination process, there just isn't any such thing as the national popular vote. For better or for worse, the national party created pledged delegates to reflect the popular will. The national party then empowered each state party to come up with its own method for selecting the delegates, subject to approval.
As a result, there is no uniform voting procedure; adding up the total "votes" is really a meaningless exercise (which I've spent too much of my time doing). It should be noted that Obama leads in this metric, adding another layer of dishonesty to Clinton backers who claim she leads the popular vote, but that fact shouldn't count in Obama's favor.
What matters is that Barack Obama has won a clear majority of the delegates selected by the people. The fact that Hillary Clinton has spent the past few days trying to obscure that fact tells you all that you need to know about her commitment to democracy.
© Jed Lewison