I've attempted to total primary popular vote totals for Clinton and Obama, as well as actual caucus voters totals for each (NOT state convention delegate totals). For caucuses the numbers are not always straightforward to calculate, as noted by a number of commentators on kos. For some caucus states, what CNN gives as "state delegate" totals are in fact actual caucus voter tallies (Nebraska, Idaho, Colorado, Alaska, North Dakota). These are simple. For a few states (Iowa, Nevada, Washington) I could not find tallies for the actual individual caucus voters. So I tracked down estimated attendance figures for these caucuses and multiplied these by the percentages (decimal figures) received by each candidate either in entrance polls (Iowa, Nevada - CNN) or the percentage of state delegates each candidate received (Washington). The results below the fold:
If we do not include the popular vote totals from the disputed Florida and Michigan primaries then Obama has received approximately 8,379,000 votes (exact number I calculated was 8,378,604, but this is obviously an estimate so I rounded to the nearest thousand). Clinton has received about 8,098,000 votes (exact number calculated 8,098,073). Thus Obama is leading in the popular vote by around 280,000. The totals are close, but I am confident that Obama is actually in the lead by at least a couple of hundred thousand.
What if we include the popular vote totals from Florida and Michigan? (a reminder - the DNC asked candidates to withdraw from these races after state democratic organizations moved their primary dates forward in violation of DNC rules. Obama pulled his name off the ballot in Michiga, Clinton left hers on, although stating that she recognized the primary would "mean nothing". In Florida both candidates' names were on the ballot. Both campaigns vowed not to campaign there, but both did so surreptitiously. Clinton was arguably more active in doing so than Obama. After losing the South Carolina primary, Clinton suddenly made the "disenfranchisement" of Florida and Michigan Democratic voters [arguably by their own party organizations] her personal cause celebre).
For Florida we have popular vote totals for each candidate that we can add to the totals already calculated. For Michigan we have a popular vote total for Hillary only. I arbitrarily alloted Obama 3/4 of the "uncommitted" slate that won 40% of the vote in Michigan.
With Florida and Michigan added in Hillary leads. She has about 9,283,000 (exact figure: 9,283,432). Obama has about 9,126,000 (exact: 9,125,967). So CLINTON then has a lead of about 157,000.
The popular vote totals are close, no doubt about it. Any claim that Hillary is substantially "ahead" in the popular vote is dubious.
Personally I think that including the Florida and Michigan popular votes in a total calculation is dubious, given their state parties' refusal to follow party rules and the subsequent confusion. But I offer both calculations and readers can decide what they think.
UPDATED: Following Michiganliberal's mention of his using exit polls in Michigan to estimate what Obama and Clinton would have gotten in the popular vote had Obama and Edwards been on the ballot, I looked at CNN exit polls which came up with a Clinton 46%/ Obama 35% breakdown and multiplied those numbers by the total votes in Michigan.
My revised estimate of popular vote totals including Michigan and Florida then becomes Clinton: approx. 9,228,000 (exact calculation: 9,228,446). Obama: approx. 9,155,488 (exact: 9,155, 488). So in this estimate clinton is up by about 73,000.
I neglected to state above that I calculated Maine pop vote totals based on Democratic party figure for total caucus attendance X state delegate percentages.