The "superpredators" line comes from a 1996 speech in New Hampshire, where Clinton spoke in support of the 1994 Violent Crime Control and Law Enforcement Act, which her husband, Bill Clinton, had signed in to law.
"We’re making some progress," Clinton said. "Much of it is related to the initiative called ‘community policing.’ Because we have finally gotten more police officers on the street. That was one of the goals that the president had when he pushed the crime bill that was passed in 1994."
Provisions of the act included a ban on some assault weapons, more funding for community policing and an expansion of the death penalty. The legislation, which was championed by Bill Clinton as a way to reduce the number of African-Americans being killed in drug-related incidents, has drawn criticism in recent years for sending disproportionate numbers of African-Americans to prison.
The "superpredator" remark, which Priebus and Trump referenced, was in the same speech a few lines later.
"But we also have to have an organized effort against gangs," Hillary Clinton said in a C-SPAN video clip. "Just as in a previous generation we had an organized effort against the mob. We need to take these people on. They are often connected to big drug cartels, they are not just gangs of kids anymore. They are often the kinds of kids that are called superpredators — no conscience, no empathy. We can talk about why they ended up that way, but first, we have to bring them to heel."
The full context of this incident does link children and superpredators, but nowhere in the speech does she directly label African-American youth this way.