Here's an interesting postscript to the saga of Mark Penn, who stepped down from his role as Hillary's chief strategist yesterday:

Penn had an earlier version of the infamous 3 A.M. ad that was much more of a negative spot attacking Barack Obama, and the attack prompted objections from other senior Hillary advisers, a Hillaryland source familiar with internal discussions over the ad tells me.

Among those senior advisers who objected to the ad's negative content was senior ad guru Mandy Grunwald, who's clashed with Penn in the past, the source says.

Just after Hillary's Ohio and Texas wins, Penn credited the actual ad, which contained no direct hit on Obama, with breaking his momentum.

But the version that did this -- to the extent that the ad worked -- was a later, and more positive spot, than one initially proposed by Penn, the source says.

"This was the way it was originally conceived," the adviser says. "It did not say the words `Barack Obama.' But there was a contrast part. It had a clear hit on Obama and it also had a much more negative feeling with the music."

The adviser continues: "The original ad asked, Who would you prefer answering the call -- someone with strength and experience, or someone who's untested?"

The clash over the ad underscores yet again the extent to which Penn clashed with other senior Hillary advisers about the campaign's message and direction. Some Hillary advisers hope that Penn's departure will signal less reliance on heavy-handed assertions about Obama's supposed weakness in comparison with Hillary and more of an emphasis on humanizing Hillary and showcasing her leadership abilities.

The disagreement over the ad also undercuts Penn's own justification for the ad. Shortly after news of the ad broke, Penn described the ad during a conference call with reporters as "a positive spot" with "very soft images."

The Hillary campaign and Penn's office both declined to comment on the clash over the ad; Grunwald didn't return repeated calls.