Where does the expression “lipstick on a pig” come from?

Linguist Ben Zimmer takes a look at the backstory of the latest campaign kerfuffle:

When Barack Obama told a crowd at a campaign event on Tuesday, “You can put lipstick on a pig, but it’s still a pig,” the McCain campaign swiftly took offense, claiming the analogy was directed at vice-presidential nominee Sarah Palin. Obama campaign spokeswoman Jen Psaki countered the accusation, saying, “That expression is older than my grandfather’s grandfather and it means that you can dress something up but it doesn’t change what it is.” Is the expression really that old?

read the rest: Where does the expression “lipstick on a pig” come from? – By Ben Zimmer – Slate Magazine.