I think Obama has lost the nomination with his own behavior (plus the antics of his campaign) since last Tuesday. He lost a lot of momentum with the Texas, Ohio and Rhode Island defeats and since then has behaved with petulance and arrogance. While there is no one thing, there have been a lot of smaller events adding up to a really profound loss of electoral legitimacy.
First are the Texas reports of caucus shenanigans after HRC clearly won the popular vote in the state. It made very real the way in which the structure of the caucus was unfairly penalizing Hillary supporters. On top of the already problematic structural issues there are the reports of belligerent and possibly criminal acts by Obama supporters to try to exacerbate the situation. I note that most of the Texas counties that have not reported their caucus results (scroll to the second Texas map near the bottom of the page) are pro-Clinton. They are small and even if they go strongly for her, won't likely change Obama winning the caucus, but it could significantly affect the final delegate count.
When even Media Whore outlets like the WaPo have taken note of the disparity between the primaries and the caucuses, the fact that you've won a caucus rather than a primary becomes a delegitimizing factor with voters who are not already strongly committed to you. If Obama claims victory in Texas on the basis of the caucus after having lost the popular vote, this will be little different than Bush claiming victory over Gore - technically correct, but not accepted as legitimate.
The weak response to the "3:00 AM phone call" ad did more damage to Obama than to HRC. Rice could only speak with authority about her own candidate, and she cut him off at the knees. All the Hillary campaign has to say is "No, our girl is ready, but nice to know you admit your guy's not up to the job, kthxby."
The Monster and Archie Bunker gaffes form a pair of bookends to something that has become an increasing irritant to rank and file Dem voters - the derisive attitude shown towards people who are not "on the bandwagon." If someone does not support Obama, the fault lies with them, not with the candidate, or that is the message coming through loud and clear to the Reagan Democrats. It fits in with the not very subtle accusations of racism against core Hillary supporters; they don't really like her, but are voting their deep, secret racist impulses. This actually started in Iowa with the extravagant praise of whites who voted Obama, explicitly noting that they weren't falling for racist BS, which immediately cast doubt on whites who didn't vote Obama. It became the dominant meme for a while in New Hampshire to try to explain away Obama's loss, and then went mainstream for a few weeks, when Obama had to admit that his campaign was deliberately trying to catapult the racist propaganda. The Archie Bunker reference is yet another attempt to call Hillary supporters racists.
This comes across badly in two ways. First, the "Archie Bunker" reference insults voters directly. People who might grudgingly allow that HRC or people campaigning for her made remarks that someone might be able to construe as possibly being racist won't accept that accusation made against themselves. Second, and this is more about the attacks on HRC herself, they come across as simply rude, the mark of people who don't respect others. The monster comment went down sideways with many, many voters. As I have said and as has been said by a number of other bloggers, Hillary's support is strong and diverse, and they feel insulted on her behalf over such comments, especially after the months of battering she has received, especially from a candidate who markets himself as a unifier, a nice guy, a conciliator, etc. He undermines the image of himself he has been projecting, and this damages his legitimacy.
Then there are the NAFTA lies. When another government says, "Erm, um, no, you actually did tell us you were lying to the voters and not to be worried by your campaign rhetoric," somebody has some 'splaining to do. This will not do him any good with blue collar voters, who tend to know about NAFTA and care what politicians say. Given that the economy is tanking, ordinary voters want straight answers on economic questions.
Now, today, there are three significant developments. First, Obama fairly strongly dismisses being on a unity ticket with Hillary. There's some equivocating, but he's not going to give an inch. He's pretty much between a rock and a hard place, of course. Say yes, he'd consider it, and his support among super delegates collapses like the house of cards that it is. Fail to agree to it, and he becomes the one refusing to unify the party and playing chicken with Dem fortunes in November. It reinforces the sense that his campaign is both arrogant and immature.
Next, Obama dismisses the possibility of a "firehouse" primary in Michigan, which raises all sorts of questions. Is he trying to force a caucus on a primary state? Do his own internal polling numbers show that he's not going to get more delegates than he might collect via "uncommitted" delegates all going to him? The real answer lies in the final development of the day.
Finally, and this is the nail in the coffin, James Carville pulls the ultimate gotcha on live TV. Read the exchange between Carville and David Wilhelm on Wolf Blitzer's show this AM. (Transcript here on Taylor Marsh.) Basically, Carville says HRC will put $15 million of her own money up to pay for new primaries in Florida and Michigan, since both the states and the DNC say they would like to do so but can't afford the cost. Will Obama raise $15 million in matching funds from his own vaunted money machine and give the voters of these states a legitimate, sanctioned, no-equivocations primary voting opportunity?
The Hillary campaign hit this one out of the ballpark and into the next county. The rock and hard place of the VP suggestion just became a lady or tiger situation. Obama cannot afford to be seen losing big states again to HRC (and he will lose MI and FL), but now he is the person in the position of preventing those votes from being cast. If he stonewalls the votes, the fury of HRC supporters at the convention will be epic and they will demand that FL and MI be seated as is. If he can bully the credentials committee into any solution other than seating as-is, he will lose all legitimacy with HRC supporters, who will either write her in, vote McCain or stay home in November.
Any claim he tries to make about how pledged delegates represent the will of the people is DOA now. Between the circus of the Texas Two-step and Obama's refusal to even allow MI and FL primaries to take place, he cannot maintain the claim to be the popular choice. How can his Texas caucus votes be more legitimate than Hillary's Texas primary votes? Moreover, he looks like he's afraid to put his money where his campaign rhetoric is and stand up to a vote.
What all of this points to, however, is one of the deep, negative themes that has been present in his campaign from the beginning, that people who do not support him are not legitimate voters and their opinions should count for nothing. People who vote for Hillary are Archie Bunkers, "low information" people who vote for "monsters" and who need to be shoved around, harangued, locked out of polling places. They will simply fall into line after he is nominated and support him, of course, but his high-minded followers cannot be asked to stoop to support anyone else.
Hillary supporters are accused of being racists, of being war-mongers, of not understanding just what a heinous human being she really is, of being stupid, old, uneducated yahoo bitches. Their dissenting opinions about key events and policy decisions (what these acts and policies mean, how they relate to each other, how important they are on their own and in relation to other acts and policies) are scorned and attacked.
The root cause of Obama's loss of electoral legitimacy is his campaign's refusal to accept that he might, very legitimately, not be the nominee.