Shankar Vedantam had a significant article in the Washington Post that essentially explains the campaign that John McCain has been running as an indirect way to fire up their own base:
As the presidential campaign heats up, intense efforts are underway to debunk rumors and misinformation. Nearly all these efforts rest on the assumption that good information is the antidote to misinformation.
But a series of new experiments show that misinformation can exercise a ghostly influence on people's minds after it has been debunked -- even among people who recognize it as misinformation. In some cases, correcting misinformation serves to increase the power of bad information [...]
Political scientists Brendan Nyhan and Jason Reifler provided two groups of volunteers with the Bush administration's prewar claims that Iraq had weapons of mass destruction. One group was given a refutation -- the comprehensive 2004 Duelfer report that concluded that Iraq did not have weapons of mass destruction before the United States invaded in 2003. Thirty-four percent of conservatives told only about the Bush administration's claims thought Iraq had hidden or destroyed its weapons before the U.S. invasion, but 64 percent of conservatives who heard both claim and refutation thought that Iraq really did have the weapons. The refutation, in other words, made the misinformation worse.
A similar "backfire effect" also influenced conservatives told about Bush administration assertions that tax cuts increase federal revenue. One group was offered a refutation by prominent economists that included current and former Bush administration officials. About 35 percent of conservatives told about the Bush claim believed it; 67 percent of those provided with both assertion and refutation believed that tax cuts increase revenue.
In a paper approaching publication, Nyhan, a PhD student at Duke University, and Reifler, at Georgia State University, suggest that Republicans might be especially prone to the backfire effect because conservatives may have more rigid views than liberals: Upon hearing a refutation, conservatives might "argue back" against the refutation in their minds, thereby strengthening their belief in the misinformation. Nyhan and Reifler did not see the same "backfire effect" when liberals were given misinformation and a refutation about the Bush administration's stance on stem cell research.
The logic here can be explained by the decades-long project by conservatives to delegitimize collective trusted sources - in particular, the "liberal media" - and cultivate their own. When conservatives hear about the Duelfer report, they can easily access a refutation from across the spectrum of wingnuttia, written by Stephen Hayes or Hugh Hewitt or some other wingnut welfare recipient. When they hear that tax cuts don't increase revenue, they have dozens of bits and pieces of information they can store in their minds to refute the refutation. When they hear an obvious lie in one of John McCain's ads called out by a fact-checking organization, they can hear Karl Rove tell them that the fact-checkers are biased.
Collective trusted sources aren't going to be much of a help here among your hard-core wingnuts (among moderates and independents, the type who say "all politicians are full of it and I think for myself," it probably won't either). It is not enough to show a chart with verifiable facts about how earnings for everyone but those with professional degrees are dropping in the Bush economy - wingnut supply-siders argue the economy's doing great, and that chart was probably from some liberal think tank (it was from the Census bureau). It is not enough for someone like Joe Klein to plainly state the facts of John McCain's health care policy, which amounts to a huge tax increase on the middle class (not enough has been made of this. McCain wants to tax employer-provided benefits as income, and the goal is to get employers to drop their benefits packages, leaving the individual on their own to manage a largely unregulated individual insurance market armed with a tax credit too meager to pay for decent coverage. McCain's core philosophy about health care is that Americans have TOO MUCH of it, and if they were forced to buy it themselves, they would buy less.) - he's part of the liberal media. US News and World Report can can chronicle John McCain's journey from maverick to liar, and so can the National Journal and just about every major media organization. But they are just more liberal house organs.
In fact, it's not enough for someone like Alan Greenspan to admit, several years too late, that McCain's plan to "finance tax cuts with borrowed money" is distasteful, or even for McCain's own economic adviser to admit that tax increases are inevitable for the next President AND that McCain is lying about this because tax cuts for Republicans are "a brand, and you don't dilute the brand" - there's a whole industry of economic denialists who will spin and shape and distort to tell you that federal revenues are bigger under Bush, and tax cuts equal increased revenue, and all the other discredited arguments.
Which is why Meghan Kelly's demolition of Tucker Bounds today on Fox News is arguably more important than the independent analyses or comprehensive takes from sources that ought to be trusted more.
You see that Bounds falls back on "you can't trust what Obama will say because he voted to raise taxes 94 times," etc. He's trying to delegitimize anything that comes out of Obama's mouth. And for some wingers, that will be enough. But seeing this argument play out on conservative media is far more likely to be impactful to those who have seen traditional sources trashed and conservative sources elevated and made trusted over the years. "Why is John McCain saying Obama will raise taxes on the middle class when he’s not?" is a pretty compelling argument coming from an embedded conservative trusted source, I would imagine. And Bounds had no answer for it.
We all have the power to be trusted sources in our spheres of influence. Instead of passing around links to the New York Times saying something or Time saying another, the only way to persuade in an environment of diminishing trusted sources is to create your own arguments. Cracks in the facade like Meghan Kelly showed today are not going to be plentiful, important as they may be.