In a presidential race that seems to include every possible political strategy, one element has barely been visible. There have been no high-impact independent groups along the lines of the Swift Boat Veterans for Truth, the group that played a prominent role in attacking John Kerry four years ago.
Although none of these outside groups has generated big headlines, it hasn't been for lack of trying.
On Wednesday, for example, two groups were holding simultaneous conferences at the National Press Club, a sort of ground zero for Washington press conferences.
One room featured Steve Kest, executive director of ACORN, the community organizing group that's fighting back against Republican accusations that it's stuffing the voter rolls with nonexistent people.
"We see voter intimidation; we see a huge problem with these no-match, no-vote laws," Kest said as he announced lawsuits and a new cable TV ad.
Out the door and down the hall, the America Deserves Better PAC was unveiling what it called a Final Ad Blitz to Defeat Obama.
This event was actually more of a campaign rally, with Sacramento radio host Mark Williams as keynote speaker. "We are the shining city on the hill," Williams told the crowd. "And there are those around Barack Obama who would like to extinguish those lights. We're not going to let that happen."
But the group's ad blitz turned out to be one new ad, and it wasn't clear whether America Deserves Better has the money to put it on the air.
Things deteriorated as Williams got into an argument with a woman who supports Obama. As she walked out, Williams called after her: "Excuse me, ma'am. I paid you the courtesy. You can pay me the courtesy too, you very rude old lady."
And so it's gone with the independent voices in the presidential campaign — accusations, a fair amount of name calling, but not enough money.
Some wealthy donors were put off by the complexity of campaign finance law. But mainly, the problem was the whipsawing of the stock markets.
After the Dow Jones industrial average's record 777-point plunge last month, wealthy donors didn't have so much wealth.
In contrast, one donor to the American Issues Project gave nearly $3 million for an ad in August linking Barack Obama with former militant Bill Ayers.
Chris LaCivita from Swift Boat Veterans for Truth produced the ad. He says they had more ideas for going after Obama, but they were stymied.
"We started a conversation that a lot of people recognized had an impact. But again, if you don't have the resources to keep the conversation going, kinda makes it hard," LaCivita says.
Even if the money is there, this sort of attack ad may not work as well as it used to.
A veteran of liberal groups, Tom Matzzie, says these ads can't get a good media ride anymore, thanks to Internet-based fact-checking.
"The swift-boaters of the future are not going to be broad spectrum. They're going to be narrowcast, is my view," he says.
That is, aimed at demographic niche groups, where they might not draw so much scrutiny.
Matzzie says some low-profile, state-level groups are this year's success stories.
"Before the campaigns themselves start spending money, it helps to have someone else out there stoking the fires to keep the issue debate in a good place," he says.
So months and months ago, Progress Now and its state affiliates started building grass-roots networks, laying the groundwork for a Democratic campaign.
Republicans don't have any counterpart to this — so far.