Jeralyn, you are right to point out that he is not quoting any surveys to back up his assertion, because if he did... the numbers tell a diferent story...

For example, as wasabi posted earlier, this is one source (Ras) that shows that Obama would have a harder time getting Clinton supporters:

"The division in the Democratic Party is highlighted by the fact that just 71% of Democratic Primary voters now say they will vote for Hillary Clinton in the general election campaign. If Barack Obama is nominated, 64% of Democratic Primary voters are ready to vote for him. The way in which the Democratic Nomination is resolved will ultimately determine whether the nominee will enjoy stronger support from the party's base."

Now I don't offhand have statistics to back it up, but I've got to believe that the number of working class Democrats who might fall under the "Reagan Democrat" rubric is larger than, say, the number of African-American voters.

But even assuming they are roughly same in number, the Reagan-Democrats present an even greater problem, by far, come the general election because:

1. They are concentrated in the major swing states (OH, PA, MI, and FL).
   
2. They traditionally swing their voters from Democrat to Republican, instead of merely sitting the election out (the likely outcome if A-As refuse to vote for Hillary). This means their likely voting behavior has twice the force.

That's exactly what Obama did with his infamous "I'll get all of her voters, but will she get all of mine" comment, and it's exactly what Markos is doing in that quote.  The instinctive reaction to being taken for granted is to respond, "Oh yeah?  I'll show YOU!" which isn't the sort of reaction you want to provoke when your goal is party unity.

Is there a single person among the prominent Obama supporters in the blogosphere (Markos, of course, sits at the head of the food chain) who understands the big picture, the need for unity in November?  If Obama were really as much of a sure thing as these folks tell us, what would the point be of continuing the negativity?

This oft-wielded cudgel to silence feminists who cry foul at sexism expressed by political allies is wrong for the following reason, which I cannot state any more succinctly than this: When someone engages in divisive behavior, any resulting division is their responsibility.

A better term would be "nuclear option".  While overturning the outcome of the pledged delegate race is "legal" based on party rules, the likelihood is that it would obliterate the coalitions that form the backbone of the party.  It's use, therefore, is an extremely grave step that should be carefully considered.

As an aside, I don't see the popular vote totals as a valid marker of the winner because the disparity between voting turnout in caucus versus primary states.  You could argue that if more states held primaries instead of caucuses that Clinton would have gained more votes and possibly more delegate but that is just pure speculation.  Besides if the popular vote was the determining factor we'd have President Gore taking his victory lap right now.  Sometimes life's unfair.

In any event, were the superdelegates to veto the pledged delegate winner, there should be a more compelling rationale than "because the rules allow for it".  The effect of such a reversal on the voters who supported Obama could have lasting consequences for this election cycle and beyond.  

In my opinion the purpose of the superdelegates holding the power to nullify the outcome pledged delegate contest is to prevent the case where nominating the pledged delegate winner would do serious harm to the Democratic party and its prospects in the general election.