Ben Smith and Byron Tau have a great article up at Politico about the origins of birtherism, the obviously false belief that President Obama was not born in the United States and is, therefore, ineligible to be President. The answer may surprise: This particular fantasy began on the left, not the right. The full expose is worth a read.
Let it be said: Conspiracy theories are not the provenance of any particular political ideology. They cater to a cast of mind that is as often found among liberals as conservatives. The difference - and it is an important one - is that prominent liberal politicians tend not to embrace such foolishness while several prominent conservatives continue to wink at the birthers and their ridiculous claims.