By David Paul Kuhn - August 3, 2009

Fully 35 percent of Democrats believe George W. Bush had advance knowledge of the 9/11 terrorist attacks. Fully 28 percent of Republicans believe Barack Obama wasn't born in the United States.

Meet the fanatical third.

The tale of two conspiracy theories is the tale of the most polarized among us. The two statistics are based on a poll apiece. Neither is an exact measure. Yet, lots of liberals say take the "birther" poll on face value. Lots of conservatives say take the "truther" poll on face value. So let's listen to both sides.

The unsurprising conclusion: you can't reason with arch partisans.

On Friday, I published a post wondering why the mainstream media was paying exponentially more attention to the "birther" movement now. The 2008 campaign ended about eight months ago, after all.

The recent obsession over this fringe topic effectively blends conservatives with a fringe belief. The end result, the media has been making conservatives look like kooks.

That's because they are, according to many liberals who emailed me last Friday. The polar camp, the "birthers," sent me an even larger onslaught of emails; many were infuriated that I had inferred they were kooks.

The liberal emailers were armed with a poll. The Daily Kos, the mega-activist liberal blog, commisioned a Research 2000 poll that was coincidently also published last Friday. The poll reported that only 42 percent of Republicans believe Obama was born in the United States, while 30 percent were unsure and 28 percent said he was born elsewhere.

Most striking, there was a broad similarity between that result and a Rasmussen poll taken in the spring of 2007. That poll found that only 39 percent of Democrats believed W. Bush did not have advance knowledge of the 9/11 terrorist attacks, while 26 percent said they were unsure and slightly more than one third of Democrats believed W. Bush knew his country was going to be attacked.

"The Paranoid Style in American Politics," was the title of historian Richard Hofstadter's famous Sixties essay. "I call it the paranoid style," he wrote, because "no other word adequately evokes the sense of heated exaggeration, suspiciousness, and conspiratorial fantasy."

Most conspiracy theorists' fidelity is to theory, not truth. They tend to uphold a belief despite the facts. The possible, however improbable, trumps the logical. And it's futile to attempt to disprove their belief. It's like debating with those who believe the world is flat.

But about one third of Democrats and Republicans want to believe the world is flat, metaphorically speaking. Perhaps it's that simple. Or, do these questions really serve as nets that capture extreme partisans?

Consider that southerners are most likely to believe Obama was born abroad. Northeasterners are least likely. The former is the most conservative region, the latter is the most liberal. And it's no coincidence that nearly all Democrats believe Obama was born in the United States and nearly all Republicans believe W. Bush had no prior knowledge of the 9/11 attacks.

The disparate treatment of the two conspiracy theories is unmistakable. More Democrats fell into the "truther" camp than Republicans fall into the "birther" camp. But the mainstream media has covered the "birther" poll far more vigorously. It's easy to understand, unless one is invested in the opposing camp, why these incongruities irk the political right.

But the poll results stir up larger questions concerning our polarization. Neither party can wholly disavow their fanatical fringe. That fringe could, one might wager, be anywhere between a fifth to two-fifths of both major parties. And that means, this fringe is endemic to our politics.

The culprits of our polarization are many. Between 1960 and 2005, one study found that ideological activist groups of all political persuasions increased sevenfold.

Gerrymandering of congressional districts has maximized liberals in liberal districts and conservatives in conservative districts. This has left our congress-people more polarized.

Today, conservatives and liberals can join vacation tours attended by only their side of the debate or join dating services to court only the like minded. At night, one side watches only MSNBC and the other side only Fox News. And when people are around likeminded individuals, one study found, their viewpoints only become that much more extreme.

We are living the result. After his first six months in office, Gallup found that only 23 percent of Republicans approved of Obama. After six months in office, Gallup found that only 28 percent of Democrats approved of W. Bush. Now travel back four to five decades.

After six months in office, 60 percent of Republicans approved of John F. Kennedy. After six months in office, 51 percent of Democrats approved of Richard Nixon. And lest we forget, Nixon and Kennedy both won by less than a percentage point.

We are ever more polarized today and so may be the conspiracies. The less each base understands the other side perhaps the more outlandish the theories become, in order explain the hold of the other side.

A few years ago, an Emory psychologist scanned the brains of self-described partisans. Partisans were able to notice the hypocritical statements of the opposing candidate but not the inconsistencies of their preferred candidate. Ideology, it was determined, showed effects similar to drug addiction.