When this contest began, Obama was clearly the most electable candidate. His widespread appeal among independents and even crossover Republicans, particularly in such a blue wave year, made any general election outcome a forgone conclusion. His most difficult task would be to win the primary against a very strong array of candidates and a hostile establishment. But that was before the kind of campaign you decided to run.
You have succeeded in making Obama less electable. Not unelectable by any means, but certainly the General will be much more interesting than it should have been. Your strategy has consisted of intentionally driving wedges between democratic groups, as well as attacking the legitimacy of Obama's victories and the entire process.
These tactics, while quite similar to ones that a Republican would use, are sadly much more effective when employed by a fellow Democrat. You see if all of these things had been employed after the primary, from the outside against "our candidate," they would have been viewed through a much different lens. All Democrats, around the country, would have pushed back in a united front against the "right wing smears." Even the mainstream media would have interpreted them differently. Most importantly, individual voters would have largely tuned them out, seeing them for what the obviously were, had they been coming from Rush Limbaugh and Bill O'Reilly. But the tactics came from you, you of the highest credibility with the most loyal Democrats, so of course they got a 2nd, 3rd, and 57th look. So now we see poll after poll where Obama garners 70% or even less of the Democratic vote. The fact that despite this Obama continues to be ahead of or tied with McCain is testament to what an incredible candidate he really is.
Come this November, if McCain garners more crossover Democrats than Obama gains Republicans, it will be a terrible shame, and it will be your shame. One candidate started with innate crossover appeal. The other started uniquely despised by his own party's base. It should not have even been close.
Don't let this become your legacy. You must work every day between now and November to repair as much of the damage you have wrought as you can. If you succeed in this, these shameful past 3 months will be largely forgiven and forgotten - a footnote to a shining moment in history. If you fail, it will haunt you and the Democratic party for generations.