Why is the mascot of the presidential parties an elephant and a donkey?

Answer 1

The donkey was first used in a political cartoon to represent the stubborn Andrew Jackson (who was also known as a jackass...and not necessarily for his political views). In following Cartoons, the donkey was dressed in lion's skins and scaring other animals out of a zoo. Each of these animals represented a different party or idea. Since the only animal more powerful than a lion is an elephant, an elephant was drawn with the words "Repulican Vote" written on it and it was chasing the donkey out of the zoo. It was originally used as a tactic to show the growing power of the GOP and the waning popularity and strength of the Democrats.

Answer 2

The first democrat Andrew Jackson's opponents labled him a donkey, and cartoonist Thomas Nast thought about it and made the donkey.

Thomas Nast also created the elephant in a cartoon.