Unlike RCP, I include the Washington state primary numbers and I assign the uncommitted vote in Michigan to Obama (there is a good argument that he should have only 75% of the uncommitted vote based on exit polling of those voters, this would narrow Obama's lead by about 60,000 votes.) I also include all caucus votes where there was not a primary (with the exception of Nebraska, whose primary was much later in time than its delegate selecting caucus.) With those adjustments, my popular vote totals have Barack Obama with a 112,000 (or 62,000 if you only allocate 75% of the Michigan uncommitted vote as discussed above) vote lead out of a total of over 35,000,000 votes cast. By my calculations, that gives Obama a 0.3% (0.15% if you allocate 75% of the Michigan uncommitted vote to Obama) lead in the popular vote with 3 primaries to go. Puerto Rico votes tomorrow and will likely push Clinton into the popular vote lead. We are hearing rumblings that South Dakota is a close race while Montana seems a safe Obama state.
While Obama is almost certain to be the nominee, there is a decent chance he will lose the popular vote to Hillary Clinton.
By Big Tent Democrat, speaking for me only