The despicable Jimmy Carter
Will Collier nicely sums up the man who wakes up every morning thanking God that there was a James Buchanan to keep him from being the worst US president:
For everybody old enough to remember what life was like under Jimmy's stupefying mixture of sophomoric self-righteousness, boundless naivete and gobsmacking incompetence, shoving Mr. Peanut back under the spotlight in his bitter dotage does nothing to help Obama, who's been looking like Carter II since a few hours after his inauguration.
And for those too young to remember history's greatest monster (thanks, Glenn), Jimmah's empty slander is just another sign of the unbecoming moral vanity at the heart of the modern Left, to say nothing of its overweening intolerance for any hint of dissent. People know good and well that being opposed to socialized medicine or trillion-dollar deficits doesn't make them racist. Calling them ugly names isn't going to make them cower away in fear--it's going to make them more convinced than ever that they're in the right.
Except for the true believer DailyKos types, lefties must cringe every time Carter opens his mouth. He's been around too long to be a right wing plant, but he's certainly king of the useful idiots for the righty cause.
UPDATE 9/18/09: James Taranto comes up with an alternate explanation that would be believable if we thought Carter was that clever: "Carter may have a conflict of interest in attacking Americans on Obama's behalf. Perhaps he secretly hopes Obama fails so miserably as to supplant Carter as the worst president of the past century."