The candidate is new, a different face on the national scene, with roots outside the continental United States and sudden, massive popularity.

With good reason, Sarah Palin has been touted as the right’s answer to Barack Obama. And in one especially important way, her abrupt rise from obscurity has given her something else in common with the Democratic nominee: she has catalyzed a fevered subculture of forwarded e-mails and viral conspiracy theories.

Now the race is on, as it was with Obama, for Palin to define herself against an onslaught of negative portrayals.

Obama’s campaign has made some attempts to challenge the Republican portrayal of her as a “living breathing replica of the middle class” (as a former White House official put it). But that narrative is being challenged online by a flood of rumor, half-truth, lies, and speculation defining her as an American exotic, a countrified stranger with mysterious but strong religious beliefs, a confusing personal story, and extreme politics.

“Information abhors a vacuum, and like Barack Obama was at first, Sarah Palin was an unknown quanity,” said the internet folklorist David Emery. “When you have all that pressure and very little information – that’s when the rumors start flying.”

Emery has been frantically sorting Palin fact from fiction on his Urban Legends website for the last week – “It’s been crazy,” he said — as has David Mikkelson, the co-creator of the urban legend clearinghouse Snopes.com.