I’m with Stoller nothing I’ve seen or heard from the 2008 primary compares with this from 2004:

Under the circumstances, it seems wrong to call this “the most bitter and negative Democratic primary in the last forty years.” The difference is just that the 2004 primary, though extremely negative at its height, also had a very short duration in terms of peak negativity before quickly morphing into the odd dynamic where Edwards refused to seriously attack Kerry and got rewarded with the VP slot.