Hillary Clinton's mafioso theory of donor management may have been workable when she looked like an overpowering juggernaut and was simply codifying her fait accompli, but now that Obama's in and proving himself a serious, attractive competitor, my guess is she's just going to piss people off. Moreover, the folks she's freezing out for "hedging their bets" will have all the more reason to pump cash into Obama's coffers, as they'll fear retribution in the event of a Clinton victory. That's the flip side of promising punishment: Everyone outside your camp now has an existential stake in making you lose.
Update: Tony, in comments, writes:
While it might sound silly for HRC to do at this point, it is something I definitely agree with ideologically.
What's so corrupt about American politics is not that how much money people give to politicians - but how many people give money to both sides. I can buy that when a large corporation gives to a candidate it's only because they have an objective interest in that candidate winning and the other losing. But when they give to multiple people in the same race, they're clearly just trying to buy favor.
It's a bit different in a primary but the general disgust still applies.
As a larger critique, that seems right. But given that Hillary and Obama are both positioned as relatively progressive Democrats with a capacity for compromise, does it hold here? One could argue that these donors are just trying to fund the best candidate to beat Bush, and want both Obama and Hillary to have the funds to make their case.