An object lesson for political partisans
Don't be so quick to assume that, since a Clinton staffer was on the recipient list of an Obama/Osama chain mail sent by a Clinton volunteer (details here) that that means the campaign had to know about the smear.
First of all, the staffer apparently responded angrily to the original email at the time but didn't forward it on to the rest of the campaign.
Second, just because the staffer received it that doesn't mean they knew it was being sent by a Clinton volunteer. I'm sure staffers get all sorts of crap like this in the mail. It would be very easy for said staffer to not notice the connection of the sender to the campaign.
The lesson of this story are that partisan supporters of candidates can be both a blessing and a curse for campaigns. You need their energy to get out the vote. But you expose yourself to the possibility of them embarrassing you like this. Said partisans need to understand that their enthusiasm can lead to them doing truly stupid things. Which is one of the reasons why I always urge partisans to be careful when passing on "juicy tidbits", especially if you don't know its origins.
I got burned once during the 2004 campaign passing on one such "juicy tidbit" before I realized that it was actually a smear being propagated by a Republican outfit.
Let's be careful out there.