Last week's PBS NOW is up and online; an excellent program on dirty politics and how to smear a candidate. This quote says it all:
"In South Carolina, we know how to run negative campaigns," Rod Shealy, a veteran campaign strategist who was convicted for violating campaign laws, tells NOW. "Your challenge as a campaign is to damage your opponent without getting caught doing it."
The program's website also has an excellent timeline of the "Obama is a Muslim" smear. Worth the click.