In fact, some at the Clinton campaign may be heaving huge sighs of relief, according to Politico's Ben Smith.
If there's any immediate consequence ... it will be to morale inside a shell-shocked campaign where Penn's compensation, his attention to his business, and his gruff demeanor made him a divisive figure.
"It was very demoralizing for the staff that's working 24/7 to see him doing book tours and engaging in private sector activities," said a prominent Clinton supporter. "It was an important statement for the campaign to make to its own team."
Penn was the source of a long series of campaign flare-ups. One subsidiary of Burson Marsteller represented the controversial private security firm Blackwater. Another angered unions Clinton was courting by working for companies trying to defeat union organizing campaigns.
His firm also collected more than $11 million from Clinton's campaign through the end of February, and was owed $2.5 million more in the most recent filing, though part of that sum is polling expenses.
The Pennsylvania campaign is all but fought. And there may not be that much more campaigning to do, so the loss of Mark Penn won't make that big a difference. If Obama comes out of this with the nomination, Penn may rue the day he emphasized policy and toughness over personal appeal.
"Being human is overrated," Penn reportedly joked at a debate prep session last winter, and the remark was, to his critics, his central failing.
Indeed, Penn spent part of 2007 marketing his new book, "Microtrends," which stressed the power of tiny demographic groups, rather than broad messages. The book begins by invoking an old Volkswagon slogan, "Think Small."
"It was a revolutionary idea – a call for the shrinking of perspective, ambition, and scale," Penn wrote.
"But as Clinton thought small and targeted narrow groups – adults who care for their parents, for instance – with specific messages, Obama's broader themes often carried the day. And when it came to organizing on the ground in Iowa and elsewhere, it was Obama who proved more able to focus on the small things.
What the Mark Penn departure inevitably makes us ask is how good Clinton herself is at management and at choice of advisors. This isn't the first time Clinton's judgment has been open to question. Penn, a charmless man, played down the importance of Clinton's need to sell herself as "human," warm, and personable, according to the New York Times report on his, well, dismissal -- his "step down under pressure."
Mr. Penn also early on resisted efforts to humanize Mrs. Clinton, insisting that her personality was not a detriment and that voters would be drawn to her experience and presumed competence. He repeatedly pointed to polling data to support his position, leading to battles with other aides who later said it was the glimpses of vulnerability and humanity seen after her loss in Iowa that enabled her to rebound.
Will the Clinton campaign change -- even change dramatically during the final few primaries? Maybe. Jonathan Weisman writes in the Washington Post:
Clinton officials stressed that Penn's departure came about because of a lapse in judgment, not because of differences over campaign strategy. But the officials did not discount that, as a result of his lesser role, Wolfson and Garin may end up steering the campaign in some different directions.
Democratic consultants outside the campaign echoed those thoughts, with one, who spoke on the condition of anonymity, predicting "a less combative campaign and more focused on her strengths."
One of the most interesting aspects of Penn's tenure at the Clinton campaign has been his Rove-like insistence on what separates different groups of Americans from each other. Of course one of the most appealing qualities of Barack Obama has been his insistence on our unity -- on how, after all is said and done by the Roves and the Penns and the Clintons we are willing and able to work together.
Clinton's fractious and angry campaigning has turned her into a hawkish, red-telephone, belligerent George W. Bush-style candidate -- so much so that many Democrats say (and seem to insist) that they will split the party rather than risk another eight years of Bush. How serious they are -- and how seriously they will be taken -- is still an unknown.
