As Dave noted in his piece on how Super PACs aren't helping to remake the Democratic Party the same way they are the GOP, many liberals just aren't comfortable with the idea of donating huge sums to fund attack ads by shady outside groups. Donors like George Soros dumped millions into ads against George W. Bush in 2004 to no avail.
Alec MacGillis reflects on this disillusionment when trying to dissect why the GOP has such a massive advantage on outside spending:
This time around, rather than simply rally their friends and colleagues around an inspiring cause, these donors are also being asked to cut massive checks. And because many of them share Obama’s disdain for the excesses of a broken campaign finance system, the exercise has prompted considerable squeamishness. One bundler who has raised more than $800,000 told me there was “an aversion to the super PACs, to the whole idea of them” in the bundler’s circle. “It’s left a really bad taste in people’s mouths.” “I think it’s awful,” says another bundler who has raised more than $600,000 for the campaign this year. “There’s too much money being spent on these elections to begin with. Why would anyone want to give $5 million to a super PAC to elect a president? It’s incomprehensible. There are a lot of other things you can give your money to.” Such as? Hospitals and investigative journalism, offered the bundler.
Another donor who had contributed a six-figure sum to Priorities was already experiencing serious buyer’s remorse. “I’m very much against people who give; everyone who gives to it has made a mistake,” lamented the donor. “I should not have given [the money] I gave.” I asked whether the stratospheric sums being raised by Republicans required wealthy Democrats to set aside these sorts of qualms. After all, Obama himself adopted this logic when he grudgingly endorsed Priorities’ efforts in February. “I understand the argument, that the bad guys are using this. But it’s a question of moral standing,” the donor explained. “We should have said, ‘This is bad for America,’ and we should have appealed to the American people. . . . Our side gave into panic for short-term gain.” The fund-raiser who met with Burton and Begala in Chicago essentially agreed: “With the benefit of hindsight, they should have said no to going [the super PAC] route—it’s disgusting. I think they’re shocked at how unsuccessful they’ve been.”
As Josh Green points out, the left seems to think it can compensate for a lack of Super PAC spending with a superior grassroots organizing and field campaign. But that was the plan in the Wisconsin recall election, and things didn't go so well.
And liberals panicking and deciding to go all-in on Super PAC attack ads if Obama looks weak in August or September may not matter -- as MacGillis notes, TV ad time has to be reserved well in advance, and besides, the summer months can be critical to framing a fall campaign. The swift boat attack ads against John Kerry in 2004 were largely a summer phenomenon, having done their damage to the the central tenet of his candidacy -- his strong military record -- well before October. Ramping up the Bain attacks or some other assault on Romney late in the game probably won't swing the election.