The Black Panthers probably mostly get a bad rap because 1. white people can't tell the difference between them and the Nation of Islam and whoever all else and 2.
Eldridge Cleaver, serial rapist (who in the most ironic twist of all time became a Mormon and Republican later in life!)
Also there was that white Black Panther in Forrest Gump and all the white people were like "I am confused and disoriented by this film."