Political party symbols come from the tradition of comic strips. Since the donkey was mostly used in response to the Republican elephant, the animal doesn't so much describe the party so much as illustrates the democrats reactionary history. It's clear that the animals themselves aren't closely tied to the heart of the party. Even today the White House made it legal to bring back a certain animal's parts as trophies. That animal: the elephant. This logo comits to the party's reactionary history and paints an active picture of their thoughtful resistence to the White House. Thank you and...
Enjoy,
-Sam