According to Realclearpolitics Barack Obama leads Hillary Clinton in the popular vote by 717,262, not including Florida or Michigan. Digging a little deeper you’ll find that 650,304 of those votes come from one state: Illinois. Behind that number is a margin of 429,000 in Cook County alone. How many of those voters are actually alive is not known, but they’ll all probably vote again in November.
Those who argue the Senator from Illinois should be the Democrat nominee based on his lead in the popular vote should take note. Illinois has 21 electoral votes. It does not matter by how much you win them in the general election, and it is likely whoever the Dems nominate will win Illinois. For example,
In the 2004 [Senate] primary Obama got 464,917 votes (64.4 percent of the vote) in Cook County and 191,006 votes elsewhere, winning statewide with 52.8 percent of the vote.
Democratic turnout was 1.63 million in 1992 and 1.3 million in 2004. Bill Clinton got 776,829 votes (51.6 percent of the total) in 1992, including 435,599 votes from Cook County and 341,230 from elsewhere.
Going into the convention, Clinton will have a good argument that the states she’s won matter more than (essentially) the margin in Cook County, especially if she closes the popular vote gap. Basing the case for Obama on the popular vote could backfire if she gets within 200,000 or so.
It also makes the choice of Al Gore problematic, since he won’t have any popular votes.