The real origin of using a dressed-up pig as a symbol of wasted efforts comes from THE ETHICS OF OUR FATHERS (PIRKE AVOTH).
Chapter 6 , Mishne 2 (paragraph) in discussing he who does not occupy himself in the study of Torah, is called a Reprobate,as it is stated ( in the proverbs 11:22)" LIKE A GOLDEN RING IN THE SNOUT OF A PIG".
Says the Abrarbenel, a 15th century scholar,"a person without Torah can be compared to a swine which does not appreciate the value of the gold in its snout"..namely a pig will always be a pig regardless of gold ---or LIPSTICK.
( THE ABRARBENEL ON PIRKE AVOT by the late Rabbi Abraham Chill -p -427)
I guess eveyday that Obama is on the defensive and off-stride is a good day for the McCain campaign.However,such arguments over trite are not good for Ameica